Navigation Operations for the Magnetospheric Multiscale Mission

NASA Technical Reports Server (NTRS)

Long, Anne; Farahmand, Mitra; Carpenter, Russell

2015-01-01

The Magnetospheric Multiscale (MMS) mission employs four identical spinning spacecraft flying in highly elliptical Earth orbits. These spacecraft will fly in a series of tetrahedral formations with separations of less than 10 km. MMS navigation operations use onboard navigation to satisfy the mission definitive orbit and time determination requirements and in addition to minimize operations cost and complexity. The onboard navigation subsystem consists of the Navigator GPS receiver with Goddard Enhanced Onboard Navigation System (GEONS) software, and an Ultra-Stable Oscillator. The four MMS spacecraft are operated from a single Mission Operations Center, which includes a Flight Dynamics Operations Area (FDOA) that supports MMS navigation operations, as well as maneuver planning, conjunction assessment and attitude ground operations. The System Manager component of the FDOA automates routine operations processes. The GEONS Ground Support System component of the FDOA provides the tools needed to support MMS navigation operations. This paper provides an overview of the MMS mission and associated navigation requirements and constraints and discusses MMS navigation operations and the associated MMS ground system components built to support navigation-related operations.

Performance Characterization of a Landmark Measurement System for ARRM Terrain Relative Navigation

NASA Technical Reports Server (NTRS)

Shoemaker, Michael A.; Wright, Cinnamon; Liounis, Andrew J.; Getzandanner, Kenneth M.; Van Eepoel, John M.; DeWeese, Keith D.

2016-01-01

This paper describes the landmark measurement system being developed for terrain relative navigation on NASAs Asteroid Redirect Robotic Mission (ARRM),and the results of a performance characterization study given realistic navigational and model errors. The system is called Retina, and is derived from the stereo-photoclinometry methods widely used on other small-body missions. The system is simulated using synthetic imagery of the asteroid surface and discussion is given on various algorithmic design choices. Unlike other missions, ARRMs Retina is the first planned autonomous use of these methods during the close-proximity and descent phase of the mission.

Performance Characterization of a Landmark Measurement System for ARRM Terrain Relative Navigation

NASA Technical Reports Server (NTRS)

Shoemaker, Michael; Wright, Cinnamon; Liounis, Andrew; Getzandanner, Kenneth; Van Eepoel, John; Deweese, Keith

2016-01-01

This paper describes the landmark measurement system being developed for terrain relative navigation on NASAs Asteroid Redirect Robotic Mission (ARRM),and the results of a performance characterization study given realistic navigational and model errors. The system is called Retina, and is derived from the stereophotoclinometry methods widely used on other small-body missions. The system is simulated using synthetic imagery of the asteroid surface and discussion is given on various algorithmic design choices. Unlike other missions, ARRMs Retina is the first planned autonomous use of these methods during the close-proximity and descent phase of the mission.

Visual navigation using edge curve matching for pinpoint planetary landing

NASA Astrophysics Data System (ADS)

Cui, Pingyuan; Gao, Xizhen; Zhu, Shengying; Shao, Wei

2018-05-01

Pinpoint landing is challenging for future Mars and asteroid exploration missions. Vision-based navigation scheme based on feature detection and matching is practical and can achieve the required precision. However, existing algorithms are computationally prohibitive and utilize poor-performance measurements, which pose great challenges for the application of visual navigation. This paper proposes an innovative visual navigation scheme using crater edge curves during descent and landing phase. In the algorithm, the edge curves of the craters tracked from two sequential images are utilized to determine the relative attitude and position of the lander through a normalized method. Then, considering error accumulation of relative navigation, a method is developed. That is to integrate the crater-based relative navigation method with crater-based absolute navigation method that identifies craters using a georeferenced database for continuous estimation of absolute states. In addition, expressions of the relative state estimate bias are derived. Novel necessary and sufficient observability criteria based on error analysis are provided to improve the navigation performance, which hold true for similar navigation systems. Simulation results demonstrate the effectiveness and high accuracy of the proposed navigation method.

An Inertial Dual-State State Estimator for Precision Planetary Landing with Hazard Detection and Avoidance

NASA Technical Reports Server (NTRS)

Bishop, Robert H.; DeMars, Kyle; Trawny, Nikolas; Crain, Tim; Hanak, Chad; Carson, John M.; Christian, John

2016-01-01

The navigation filter architecture successfully deployed on the Morpheus flight vehicle is presented. The filter was developed as a key element of the NASA Autonomous Landing and Hazard Avoidance Technology (ALHAT) project and over the course of 15 free fights was integrated into the Morpheus vehicle, operations, and flight control loop. Flight testing completed by demonstrating autonomous hazard detection and avoidance, integration of an altimeter, surface relative velocity (velocimeter) and hazard relative navigation (HRN) measurements into the onboard dual-state inertial estimator Kalman flter software, and landing within 2 meters of the vertical testbed GPS-based navigation solution at the safe landing site target. Morpheus followed a trajectory that included an ascent phase followed by a partial descent-to-landing, although the proposed filter architecture is applicable to more general planetary precision entry, descent, and landings. The main new contribution is the incorporation of a sophisticated hazard relative navigation sensor-originally intended to locate safe landing sites-into the navigation system and employed as a navigation sensor. The formulation of a dual-state inertial extended Kalman filter was designed to address the precision planetary landing problem when viewed as a rendezvous problem with an intended landing site. For the required precision navigation system that is capable of navigating along a descent-to-landing trajectory to a precise landing, the impact of attitude errors on the translational state estimation are included in a fully integrated navigation structure in which translation state estimation is combined with attitude state estimation. The map tie errors are estimated as part of the process, thereby creating a dual-state filter implementation. Also, the filter is implemented using inertial states rather than states relative to the target. External measurements include altimeter, velocimeter, star camera, terrain relative navigation sensor, and a hazard relative navigation sensor providing information regarding hazards on a map generated on-the-fly.

Open-Loop Flight Testing of COBALT Navigation and Sensor Technologies for Precise Soft Landing

NASA Technical Reports Server (NTRS)

Carson, John M., III; Restrepo, Caroline I.; Seubert, Carl R.; Amzajerdian, Farzin; Pierrottet, Diego F.; Collins, Steven M.; O'Neal, Travis V.; Stelling, Richard

2017-01-01

An open-loop flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) payload was conducted onboard the Masten Xodiac suborbital rocket testbed. The payload integrates two complementary sensor technologies that together provide a spacecraft with knowledge during planetary descent and landing to precisely navigate and softly touchdown in close proximity to targeted surface locations. The two technologies are the Navigation Doppler Lidar (NDL), for high-precision velocity and range measurements, and the Lander Vision System (LVS) for map-relative state esti- mates. A specialized navigation filter running onboard COBALT fuses the NDL and LVS data in real time to produce a very precise Terrain Relative Navigation (TRN) solution that is suitable for future, autonomous planetary landing systems that require precise and soft landing capabilities. During the open-loop flight campaign, the COBALT payload acquired measurements and generated a precise navigation solution, but the Xodiac vehicle planned and executed its maneuvers based on an independent, GPS-based navigation solution. This minimized the risk to the vehicle during the integration and testing of the new navigation sensing technologies within the COBALT payload.

The new Euskalmet coastal-maritime warning system

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

Approach-Phase Precision Landing with Hazard Relative Navigation: Terrestrial Test Campaign Results of the Morpheus/ALHAT Project

NASA Technical Reports Server (NTRS)

Crain, Timothy P.; Bishop, Robert H.; Carson, John M., III; Trawny, Nikolas; Hanak, Chad; Sullivan, Jacob; Christian, John; DeMars, Kyle; Campbell, Tom; Getchius, Joel

2016-01-01

The Morpheus Project began in late 2009 as an ambitious e ort code-named Project M to integrate three ongoing multi-center NASA technology developments: humanoid robotics, liquid oxygen/liquid methane (LOX/LCH4) propulsion and Autonomous Precision Landing and Hazard Avoidance Technology (ALHAT) into a single engineering demonstration mission to be own to the Moon by 2013. The humanoid robot e ort was redirected to a deploy- ment of Robonaut 2 on the International Space Station in February of 2011 while Morpheus continued as a terrestrial eld test project integrating the existing ALHAT Project's tech- nologies into a sub-orbital ight system using the world's rst LOX/LCH4 main propulsion and reaction control system fed from the same blowdown tanks. A series of 33 tethered tests with the Morpheus 1.0 vehicle and Morpheus 1.5 vehicle were conducted from April 2011 - December 2013 before successful, sustained free ights with the primary Vertical Testbed (VTB) navigation con guration began with Free Flight 3 on December 10, 2013. Over the course of the following 12 free ights and 3 tethered ights, components of the ALHAT navigation system were integrated into the Morpheus vehicle, operations, and ight control loop. The ALHAT navigation system was integrated and run concurrently with the VTB navigation system as a reference and fail-safe option in ight (see touchdown position esti- mate comparisons in Fig. 1). Flight testing completed with Free Flight 15 on December 15, 2014 with a completely autonomous Hazard Detection and Avoidance (HDA), integration of surface relative and Hazard Relative Navigation (HRN) measurements into the onboard dual-state inertial estimator Kalman lter software, and landing within 2 meters of the VTB GPS-based navigation solution at the safe landing site target. This paper describes the Mor- pheus joint VTB/ALHAT navigation architecture, the sensors utilized during the terrestrial ight campaign, issues resolved during testing, and the navigation results from the ight tests.

Comparative advantage between traditional and smart navigation systems

NASA Astrophysics Data System (ADS)

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

2013-03-01

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. This work was supported by the Original Technology Research Program for Brain Science through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology(No. 2010-0018847).

Context-Aware Personal Navigation Using Embedded Sensor Fusion in Smartphones

PubMed Central

Saeedi, Sara; Moussa, Adel; El-Sheimy, Naser

2014-01-01

Context-awareness is an interesting topic in mobile navigation scenarios where the context of the application is highly dynamic. Using context-aware computing, navigation services consider the situation of user, not only in the design process, but in real time while the device is in use. The basic idea is that mobile navigation services can provide different services based on different contexts—where contexts are related to the user's activity and the device placement. Context-aware systems are concerned with the following challenges which are addressed in this paper: context acquisition, context understanding, and context-aware application adaptation. The proposed approach in this paper is using low-cost sensors in a multi-level fusion scheme to improve the accuracy and robustness of context-aware navigation system. The experimental results demonstrate the capabilities of the context-aware Personal Navigation Systems (PNS) for outdoor personal navigation using a smartphone. PMID:24670715

Context-aware personal navigation using embedded sensor fusion in smartphones.

PubMed

Saeedi, Sara; Moussa, Adel; El-Sheimy, Naser

2014-03-25

Context-awareness is an interesting topic in mobile navigation scenarios where the context of the application is highly dynamic. Using context-aware computing, navigation services consider the situation of user, not only in the design process, but in real time while the device is in use. The basic idea is that mobile navigation services can provide different services based on different contexts-where contexts are related to the user's activity and the device placement. Context-aware systems are concerned with the following challenges which are addressed in this paper: context acquisition, context understanding, and context-aware application adaptation. The proposed approach in this paper is using low-cost sensors in a multi-level fusion scheme to improve the accuracy and robustness of context-aware navigation system. The experimental results demonstrate the capabilities of the context-aware Personal Navigation Systems (PNS) for outdoor personal navigation using a smartphone.

Open-Loop Performance of COBALT Precision Landing Payload on a Commercial Sub-Orbital Rocket

NASA Technical Reports Server (NTRS)

Restrepo, Carolina I.; Carson, John M., III; Amzajerdian, Farzin; Seubert, Carl R.; Lovelace, Ronney S.; McCarthy, Megan M.; Tse, Teming; Stelling, Richard; Collins, Steven M.

2018-01-01

An open-loop flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) platform was conducted onboard the Masten Xodiac suborbital rocket testbed. The COBALT platform integrates NASA Guidance, Navigation and Control (GN&C) sensing technologies for autonomous, precise soft landing, including the Navigation Doppler Lidar (NDL) velocity and range sensor and the Lander Vision System (LVS) Terrain Relative Navigation (TRN) system. A specialized navigation filter running onboard COBALT fuses the NDL and LVS data in real time to produce a navigation solution that is independent of GPS and suitable for future, autonomous, planetary, landing systems. COBALT was a passive payload during the open loop tests. COBALT's sensors were actively taking data and processing it in real time, but the Xodiac rocket flew with its own GPS-navigation system as a risk reduction activity in the maturation of the technologies towards space flight. A future closed-loop test campaign is planned where the COBALT navigation solution will be used to fly its host vehicle.

Interplanetary approach optical navigation with applications

NASA Technical Reports Server (NTRS)

Jerath, N.

1978-01-01

The use of optical data from onboard television cameras for the navigation of interplanetary spacecraft during the planet approach phase is investigated. Three optical data types were studied: the planet limb with auxiliary celestial references, the satellite-star, and the planet-star two-camera methods. Analysis and modelling issues related to the nature and information content of the optical methods were examined. Dynamic and measurement system modelling, data sequence design, measurement extraction, model estimation and orbit determination, as relating optical navigation, are discussed, and the various error sources were analyzed. The methodology developed was applied to the Mariner 9 and the Viking Mars missions. Navigation accuracies were evaluated at the control and knowledge points, with particular emphasis devoted to the combined use of radio and optical data. A parametric probability analysis technique was developed to evaluate navigation performance as a function of system reliabilities.

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

PubMed

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

2012-01-01

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.

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

PubMed Central

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

2012-01-01

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

Feasibility of satellite interferometry for surveillance, navigation, and traffic control

NASA Technical Reports Server (NTRS)

Gopalapillai, S.; Ruck, G. T.; Mourad, A. G.

1976-01-01

The feasibility of using a satellite borne interferometry system for surveillance, navigation, and traffic control applications was investigated. The evaluation was comprised of: (1) a two part systems analysis (software and hardware); (2) a survey of competitive navigation systems (both experimental and planned); (3) a comparison of their characteristics and capabilities with those of an interferometry system; and (4) a limited survey of potential users to determine the variety of possible applications for the interferometry system and the requirements which it would have to meet. Five candidate or "strawman" interferometry systems for various applications with various capabilities were configured (on a preliminary basis) and were evaluated. It is concluded that interferometry in conjunction with a geostationary satellite has an inherent ability to provide both a means for navigation/position location and communication. It offers a very high potential for meeting a large number of user applications and requirements for navigation and related functions.

Onboard Navigation Systems Characteristics

NASA Technical Reports Server (NTRS)

1979-01-01

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.

Analysis of navigation and guidance requirements for commercial VTOL operations

NASA Technical Reports Server (NTRS)

Hoffman, W. C.; Zvara, J.; Hollister, W. M.

1975-01-01

The paper presents some results of a program undertaken to define navigation and guidance requirements for commercial VTOL operations in the takeoff, cruise, terminal and landing phases of flight in weather conditions up to and including Category III. Quantitative navigation requirements are given for the parameters range, coverage, operation near obstacles, horizontal accuracy, multiple landing aircraft, multiple pad requirements, inertial/radio-inertial requirements, reliability/redundancy, update rate, and data link requirements in all flight phases. A multi-configuration straw-man navigation and guidance system for commercial VTOL operations is presented. Operation of the system is keyed to a fully automatic approach for navigation, guidance and control, with pilot as monitor-manager. The system is a hybrid navigator using a relatively low-cost inertial sensor with DME updates and MLS in the approach/departure phases.

Oceanic surveillance and navigation analysis, FY 72.

DOT National Transportation Integrated Search

1972-08-01

The report summarizes the Oceanic Surveillance and Navigation Analysis performed, at or under the direction of, the Transportation Systems Center under PPA FA-204 for FY72. A methodology has been developed by Systems Control, Inc. for relating the sa...

Evaluation of Design Assurance Regulations for Safety of Space Navigation Services

NASA Astrophysics Data System (ADS)

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

2005-12-01

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

Relative Navigation for Formation Flying of Spacecraft

NASA Technical Reports Server (NTRS)

Alonso, Roberto; Du, Ju-Young; Hughes, Declan; Junkins, John L.; Crassidis, John L.

2001-01-01

This paper presents a robust and efficient approach for relative navigation and attitude estimation of spacecraft flying in formation. This approach uses measurements from a new optical sensor that provides a line of sight vector from the master spacecraft to the secondary satellite. The overall system provides a novel, reliable, and autonomous relative navigation and attitude determination system, employing relatively simple electronic circuits with modest digital signal processing requirements and is fully independent of any external systems. Experimental calibration results are presented, which are used to achieve accurate line of sight measurements. State estimation for formation flying is achieved through an optimal observer design. Also, because the rotational and translational motions are coupled through the observation vectors, three approaches are suggested to separate both signals just for stability analysis. Simulation and experimental results indicate that the combined sensor/estimator approach provides accurate relative position and attitude estimates.

Distributed Ship Navigation Control System Based on Dual Network

NASA Astrophysics Data System (ADS)

Yao, Ying; Lv, Wu

2017-10-01

Navigation system is very important for ship’s normal running. There are a lot of devices and sensors in the navigation system to guarantee ship’s regular work. In the past, these devices and sensors were usually connected via CAN bus for high performance and reliability. However, as the development of related devices and sensors, the navigation system also needs the ability of high information throughput and remote data sharing. To meet these new requirements, we propose the communication method based on dual network which contains CAN bus and industrial Ethernet. Also, we import multiple distributed control terminals with cooperative strategy based on the idea of synchronizing the status by multicasting UDP message contained operation timestamp to make the system more efficient and reliable.

Development of a prototype real-time automated filter for operational deep space navigation

NASA Technical Reports Server (NTRS)

Masters, W. C.; Pollmeier, V. M.

1994-01-01

Operational deep space navigation has been in the past, and is currently, performed using systems whose architecture requires constant human supervision and intervention. A prototype for a system which allows relatively automated processing of radio metric data received in near real-time from NASA's Deep Space Network (DSN) without any redesign of the existing operational data flow has been developed. This system can allow for more rapid response as well as much reduced staffing to support mission navigation operations.

Ultra-Wideband Tracking System Design for Relative Navigation

NASA Technical Reports Server (NTRS)

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

2011-01-01

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.

Integrated Docking Simulation and Testing with the Johnson Space Center Six-Degree of Freedom Dynamic Test System

NASA Technical Reports Server (NTRS)

Mitchell, Jennifer D.; Cryan, Scott P.; Baker, Kenneth; Martin, Toby; Goode, Robert; Key, Kevin W.; Manning, Thomas; Chien, Chiun-Hong

2008-01-01

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as Automated Rendezvous and Docking, AR&D). The crewed versions may also perform AR&D, possibly with a different level of automation and/or autonomy, and must also provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Constellation Program; this is carried as one of the CEV Project top risks. The Exploration Technology Development Program (ETDP) AR&D Sensor Technology Project seeks to reduce this risk by increasing technology maturation of selected relative navigation sensor technologies through testing and simulation. One of the project activities is a series of "pathfinder" testing and simulation activities to integrate relative navigation sensors with the Johnson Space Center Six-Degree-of-Freedom Test System (SDTS). The SDTS will be the primary testing location for the Orion spacecraft s Low Impact Docking System (LIDS). Project team members have integrated the Orion simulation with the SDTS computer system so that real-time closed loop testing can be performed with relative navigation sensors and the docking system in the loop during docking and undocking scenarios. Two relative navigation sensors are being used as part of a "pathfinder" activity in order to pave the way for future testing with the actual Orion sensors. This paper describes the test configuration and test results.

Measuring the impact of enhanced kinship navigator services for informal kinship caregivers using an experimental design.

PubMed

Feldman, Leonard H; Fertig, Amanda

2013-01-01

While relative care may offer significant benefits to kin children as compared to non-relative foster care, informal kinship caregivers often experience various hardships and needs without the resources of the child welfare system to aid them. They may benefit from services provided by an expanded kinship navigator program. This study, using an experimental design, adds to knowledge about the characteristics and needs of kinship caregivers and the impact of enhanced navigator services. The relative effect of this more intensive intervention was mixed. Caregivers had many of their expressed needs met. Yet, the enhanced services group did not demonstrate: an increase in perceived social support; reduction in caregiver stress; or improvement in child behavior compared to the families receiving brief, traditional navigator services. Little difference was found in post intervention involvement in the child welfare system. Further enhancements to the model are suggested.

What Makes Patient Navigation Most Effective: Defining Useful Tasks and Networks.

PubMed

Gunn, Christine; Battaglia, Tracy A; Parker, Victoria A; Clark, Jack A; Paskett, Electra D; Calhoun, Elizabeth; Snyder, Frederick R; Bergling, Emily; Freund, Karen M

2017-01-01

Given the momentum in adopting patient navigation into cancer care, there is a need to understand the contribution of specific navigator activities to improved clinical outcomes. A mixed-methods study combined direct observations of patient navigators within the Patient Navigation Research Program and outcome data from the trial. We correlated the frequency of navigator tasks with the outcome of rate of diagnostic resolution within 365 days among patients who received the intervention relative to controls. A focused content analysis examined those tasks with the strongest correlations between navigator tasks and patient outcomes. Navigating directly with specific patients (r = 0.679), working with clinical providers to facilitate patient care (r = 0.643), and performing tasks not directly related to their diagnostic evaluation for patients were positively associated with more timely diagnosis (r = 0.714). Using medical records for non-navigation tasks had a negative association (r = -0.643). Content analysis revealed service provision directed at specific patients improved care while systems-focused activities did not.

Open-Loop Flight Testing of COBALT GN&C Technologies for Precise Soft Landing

NASA Technical Reports Server (NTRS)

Carson, John M., III; Amzajerdian, Farzin; Seubert, Carl R.; Restrepo, Carolina I.

2017-01-01

A terrestrial, open-loop (OL) flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) platform was conducted onboard the Masten Xodiac suborbital rocket testbed, with support through the NASA Advanced Exploration Systems (AES), Game Changing Development (GCD), and Flight Opportunities (FO) Programs. The COBALT platform integrates NASA Guidance, Navigation and Control (GN&C) sensing technologies for autonomous, precise soft landing, including the Navigation Doppler Lidar (NDL) velocity and range sensor and the Lander Vision System (LVS) Terrain Relative Navigation (TRN) system. A specialized navigation filter running onboard COBALT fuzes the NDL and LVS data in real time to produce a precise navigation solution that is independent of the Global Positioning System (GPS) and suitable for future, autonomous planetary landing systems. The OL campaign tested COBALT as a passive payload, with COBALT data collection and filter execution, but with the Xodiac vehicle Guidance and Control (G&C) loops closed on a Masten GPS-based navigation solution. The OL test was performed as a risk reduction activity in preparation for an upcoming 2017 closed-loop (CL) flight campaign in which Xodiac G&C will act on the COBALT navigation solution and the GPS-based navigation will serve only as a backup monitor.

The Aging Navigational System.

PubMed

Lester, Adam W; Moffat, Scott D; Wiener, Jan M; Barnes, Carol A; Wolbers, Thomas

2017-08-30

The discovery of neuronal systems dedicated to computing spatial information, composed of functionally distinct cell types such as place and grid cells, combined with an extensive body of human-based behavioral and neuroimaging research has provided us with a detailed understanding of the brain's navigation circuit. In this review, we discuss emerging evidence from rodents, non-human primates, and humans that demonstrates how cognitive aging affects the navigational computations supported by these systems. Critically, we show 1) that navigational deficits cannot solely be explained by general deficits in learning and memory, 2) that there is no uniform decline across different navigational computations, and 3) that navigational deficits might be sensitive markers for impending pathological decline. Following an introduction to the mechanisms underlying spatial navigation and how they relate to general processes of learning and memory, the review discusses how aging affects the perception and integration of spatial information, the creation and storage of memory traces for spatial information, and the use of spatial information during navigational behavior. The closing section highlights the clinical potential of behavioral and neural markers of spatial navigation, with a particular emphasis on neurodegenerative disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Linked Autonomous Interplanetary Satellite Orbit Navigation

NASA Technical Reports Server (NTRS)

Parker, Jeffrey S.; Anderson, Rodney L.; Born, George H.; Leonard, Jason M.; McGranaghan, Ryan M.; Fujimoto, Kohei

2013-01-01

A navigation technology known as LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation) has been known to produce very impressive navigation results for scenarios involving two or more cooperative satellites near the Moon, such that at least one satellite must be in an orbit significantly perturbed by the Earth, such as a lunar halo orbit. The two (or more) satellites track each other using satellite-to-satellite range and/or range-rate measurements. These relative measurements yield absolute orbit navigation when one of the satellites is in a lunar halo orbit, or the like. The geometry between a lunar halo orbiter and a GEO satellite continuously changes, which dramatically improves the information content of a satellite-to-satellite tracking signal. The geometrical variations include significant out-of-plane shifts, as well as inplane shifts. Further, the GEO satellite is almost continuously in view of a lunar halo orbiter. High-fidelity simulations demonstrate that LiAISON technology improves the navigation of GEO orbiters by an order of magnitude, relative to standard ground tracking. If a GEO satellite is navigated using LiAISON- only tracking measurements, its position is typically known to better than 10 meters. If LiAISON measurements are combined with simple radiometric ground observations, then the satellite s position is typically known to better than 3 meters, which is substantially better than the current state of GEO navigation. There are two features of LiAISON that are novel and advantageous compared with conventional satellite navigation. First, ordinary satellite-to-satellite tracking data only provides relative navigation of each satellite. The novelty is the placement of one navigation satellite in an orbit that is significantly perturbed by both the Earth and the Moon. A navigation satellite can track other satellites elsewhere in the Earth-Moon system and acquire knowledge about both satellites absolute positions and velocities, as well as relative positions and velocities in space. The second novelty is that ordinarily one requires many satellites in order to achieve full navigation of any given customer s position and velocity over time. With LiAISON navigation, only a single navigation satellite is needed, provided that the satellite is significantly affected by the gravity of the Earth and the Moon. That single satellite can track another satellite elsewhere in the Earth- Moon system and obtain absolute knowledge of both satellites states.

Parametric study of sensor placement for vision-based relative navigation system of multiple spacecraft

NASA Astrophysics Data System (ADS)

Jeong, Junho; Kim, Seungkeun; Suk, Jinyoung

2017-12-01

In order to overcome the limited range of GPS-based techniques, vision-based relative navigation methods have recently emerged as alternative approaches for a high Earth orbit (HEO) or deep space missions. Therefore, various vision-based relative navigation systems use for proximity operations between two spacecraft. For the implementation of these systems, a sensor placement problem can occur on the exterior of spacecraft due to its limited space. To deal with the sensor placement, this paper proposes a novel methodology for a vision-based relative navigation based on multiple position sensitive diode (PSD) sensors and multiple infrared beacon modules. For the proposed method, an iterated parametric study is used based on the farthest point optimization (FPO) and a constrained extended Kalman filter (CEKF). Each algorithm is applied to set the location of the sensors and to estimate relative positions and attitudes according to each combination by the PSDs and beacons. After that, scores for the sensor placement are calculated with respect to parameters: the number of the PSDs, number of the beacons, and accuracy of relative estimates. Then, the best scoring candidate is determined for the sensor placement. Moreover, the results of the iterated estimation show that the accuracy improves dramatically, as the number of the PSDs increases from one to three.

Microwave systems applications in deep space telecommunications and navigation - Space Exploration Initiative architectures

NASA Technical Reports Server (NTRS)

Hall, Justin R.; Hastrup, Rolf C.; Bell, David J.

1992-01-01

The general support requirements of a typical SEI mission set, along with the mission operations objectives and related telecommunications, navigation, and information management (TNIM) support infrastructure options are described. Responsive system architectures and designs are proposed, including a Mars orbiting communications relay satellite system and a Mars-centered navigation capability for servicing all Mars missions. With the TNIM architecture as a basis, key elements of the microwave link design are proposed. The needed new technologies which enable these designs are identified, and current maturity is assessed.

Microwave systems applications in deep space telecommunications and navigation - Space Exploration Initiative architectures

NASA Astrophysics Data System (ADS)

Hall, Justin R.; Hastrup, Rolf C.; Bell, David J.

1992-06-01

The general support requirements of a typical SEI mission set, along with the mission operations objectives and related telecommunications, navigation, and information management (TNIM) support infrastructure options are described. Responsive system architectures and designs are proposed, including a Mars orbiting communications relay satellite system and a Mars-centered navigation capability for servicing all Mars missions. With the TNIM architecture as a basis, key elements of the microwave link design are proposed. The needed new technologies which enable these designs are identified, and current maturity is assessed.

Multi-Purpose Avionic Architecture for Vision Based Navigation Systems for EDL and Surface Mobility Scenarios

NASA Astrophysics Data System (ADS)

Tramutola, A.; Paltro, D.; Cabalo Perucha, M. P.; Paar, G.; Steiner, J.; Barrio, A. M.

2015-09-01

Vision Based Navigation (VBNAV) has been identified as a valid technology to support space exploration because it can improve autonomy and safety of space missions. Several mission scenarios can benefit from the VBNAV: Rendezvous & Docking, Fly-Bys, Interplanetary cruise, Entry Descent and Landing (EDL) and Planetary Surface exploration. For some of them VBNAV can improve the accuracy in state estimation as additional relative navigation sensor or as absolute navigation sensor. For some others, like surface mobility and terrain exploration for path identification and planning, VBNAV is mandatory. This paper presents the general avionic architecture of a Vision Based System as defined in the frame of the ESA R&T study “Multi-purpose Vision-based Navigation System Engineering Model - part 1 (VisNav-EM-1)” with special focus on the surface mobility application.

Laser-based Relative Navigation Using GPS Measurements for Spacecraft Formation Flying

NASA Astrophysics Data System (ADS)

Lee, Kwangwon; Oh, Hyungjik; Park, Han-Earl; Park, Sang-Young; Park, Chandeok

2015-12-01

This study presents a precise relative navigation algorithm using both laser and Global Positioning System (GPS) measurements in real time. The measurement model of the navigation algorithm between two spacecraft is comprised of relative distances measured by laser instruments and single differences of GPS pseudo-range measurements in spherical coordinates. Based on the measurement model, the Extended Kalman Filter (EKF) is applied to smooth the pseudo-range measurements and to obtain the relative navigation solution. While the navigation algorithm using only laser measurements might become inaccurate because of the limited accuracy of spacecraft attitude estimation when the distance between spacecraft is rather large, the proposed approach is able to provide an accurate solution even in such cases by employing the smoothed GPS pseudo-range measurements. Numerical simulations demonstrate that the errors of the proposed algorithm are reduced by more than about 12% compared to those of an algorithm using only laser measurements, as the accuracy of angular measurements is greater than 0.001° at relative distances greater than 30 km.

Autonomous Precision Landing and Hazard Avoidance Technology (ALHAT) Project Status as of May 2010

NASA Technical Reports Server (NTRS)

Striepe, Scott A.; Epp, Chirold D.; Robertson, Edward A.

2010-01-01

This paper includes the current status of NASA s Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) Project. The ALHAT team has completed several flight tests and two major design analysis cycles. These tests and analyses examine terrain relative navigation sensors, hazard detection and avoidance sensors and algorithms, and hazard relative navigation algorithms, and the guidance and navigation system using these ALHAT functions. The next flight test is scheduled for July 2010. The paper contains results from completed flight tests and analysis cycles. ALHAT system status, upcoming tests and analyses is also addressed. The current ALHAT plans as of May 2010 are discussed. Application of the ALHAT system to landing on bodies other than the Moon is included

Integrated INS/GPS Navigation from a Popular Perspective

NASA Technical Reports Server (NTRS)

Omerbashich, Mensur

2002-01-01

Inertial navigation, blended with other navigation aids, Global Positioning System (GPS) in particular, has gained significance due to enhanced navigation and inertial reference performance and dissimilarity for fault tolerance and anti-jamming. Relatively new concepts based upon using Differential GPS (DGPS) blended with Inertial (and visual) Navigation Sensors (INS) offer the possibility of low cost, autonomous aircraft landing. The FAA has decided to implement the system in a sophisticated form as a new standard navigation tool during this decade. There have been a number of new inertial sensor concepts in the recent past that emphasize increased accuracy of INS/GPS versus INS and reliability of navigation, as well as lower size and weight, and higher power, fault tolerance, and long life. The principles of GPS are not discussed; rather the attention is directed towards general concepts and comparative advantages. A short introduction to the problems faced in kinematics is presented. The intention is to relate the basic principles of kinematics to probably the most used navigation method in the future-INS/GPS. An example of the airborne INS is presented, with emphasis on how it works. The discussion of the error types and sources in navigation, and of the role of filters in optimal estimation of the errors then follows. The main question this paper is trying to answer is 'What are the benefits of the integration of INS and GPS and how is this, navigation concept of the future achieved in reality?' The main goal is to communicate the idea about what stands behind a modern navigation method.

Orientation and navigation relative to water flow, prey, conspecifics, and predators by the nudibranch mollusc Tritonia diomedea.

PubMed

Wyeth, Russell C; Woodward, Owen M; Willows, A O Dennis

2006-04-01

Progress in understanding sensory and locomotory systems in Tritonia diomedea has created the potential for the neuroethological study of animal navigation in this species. Our goal is to describe the navigational behaviors to guide further work on how the nervous system integrates information from multiple senses to produce oriented locomotion. Observation of T. diomedea in its habitat has suggested that it uses water flow to navigate relative to prey, predators, and conspecifics. We test these hypotheses in the field by comparing slug orientation in time-lapse videos to flow direction in circumstances with and without prey, predators, or conspecifics upstream. T. diomedea oriented upstream both while crawling and after turning. This trend was strongest before feeding or mating; after feeding or mating, the slugs did not orient significantly to flow. Slugs turned downstream away from an upstream predator but did not react in control situations without an upstream predator. These data support the hypothesis that T. diomedea uses a combination of odors (or some other cue transported downstream) and water flow to navigate relative to prey, predators, and conspecifics. Understanding the context-dependent choice between upstream and downstream crawling in T. diomedea provides an opportunity for further work on the sensory integration underlying navigation behavior.

Position Measurement Standard Evaluation

DOT National Transportation Integrated Search

1975-02-01

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

Relative navigation and attitude determination using a GPS/INS integrated system near the International Space Station

NASA Astrophysics Data System (ADS)

Um, Jaeyong

2001-08-01

The Space Integrated GPS/INS (SIGI) sensor is the primary navigation and attitude determination source for the International Space Station (ISS). The SIGI was successfully demonstrated on-orbit for the first time in the SIGI Orbital Attitude Readiness (SOAR) demonstration on the Space Shuttle Atlantis in May 2000. Numerous proximity operations near the ISS have been and will be performed over the lifetime of the Station. The development of an autonomous relative navigation system is needed to improve the safety and efficiency of vehicle operations near the ISS. A hardware simulation study was performed for the GPS-based relative navigation using the state vector difference approach and the interferometric approach in the absence of multipath. The interferometric approach, where the relative states are estimated directly, showed comparable results for a 1 km baseline. One of the most pressing current technical issues is the design of an autonomous relative navigation system in the proximity of the ISS, where GPS signals are blocked and maneuvers happen frequently. An integrated GPS/INS system is investigated for the possibility of a fully autonomous relative navigation system. Another application of GPS measurements is determination of the vehicle's orientation in space. This study used the SOAR experiment data to characterize the SICI's on-orbit performance for attitude determination. A cold start initialization algorithm was developed for integer ambiguity resolution in any initial orientation. The original algorithm that was used in the SIGI had an operational limitation in the integer ambiguity resolution, which was developed for terrestrial applications, and limited its effectiveness in space. The new algorithm was tested using the SOAR data and has been incorporated in the current SIGI flight software. The attitude estimation performance was examined using two different GPS/INS integration algorithms. The GPS/INS attitude solution using the SOAR data was as accurate as 0.06 deg (RMS) in 3-axis with multipath mitigation. Other improvements to the attitude determination algorithm were the development of a faster integer ambiguity resolution method and the incorporation of line bias modeling.

Satellite Imagery Assisted Road-Based Visual Navigation System

NASA Astrophysics Data System (ADS)

Volkova, A.; Gibbens, P. W.

2016-06-01

There is a growing demand for unmanned aerial systems as autonomous surveillance, exploration and remote sensing solutions. Among the key concerns for robust operation of these systems is the need to reliably navigate the environment without reliance on global navigation satellite system (GNSS). This is of particular concern in Defence circles, but is also a major safety issue for commercial operations. In these circumstances, the aircraft needs to navigate relying only on information from on-board passive sensors such as digital cameras. An autonomous feature-based visual system presented in this work offers a novel integral approach to the modelling and registration of visual features that responds to the specific needs of the navigation system. It detects visual features from Google Earth* build a feature database. The same algorithm then detects features in an on-board cameras video stream. On one level this serves to localise the vehicle relative to the environment using Simultaneous Localisation and Mapping (SLAM). On a second level it correlates them with the database to localise the vehicle with respect to the inertial frame. The performance of the presented visual navigation system was compared using the satellite imagery from different years. Based on comparison results, an analysis of the effects of seasonal, structural and qualitative changes of the imagery source on the performance of the navigation algorithm is presented. * The algorithm is independent of the source of satellite imagery and another provider can be used

Differences in navigation performance and postpartal striatal volume associated with pregnancy in humans.

PubMed

Lisofsky, Nina; Wiener, Jan; de Condappa, Olivier; Gallinat, Jürgen; Lindenberger, Ulman; Kühn, Simone

2016-10-01

Pregnancy is accompanied by prolonged exposure to high estrogen levels. Animal studies have shown that estrogen influences navigation strategies and, hence, affects navigation performance. High estrogen levels are related to increased use of hippocampal-based allocentric strategies and decreased use of striatal-based egocentric strategies. In humans, associations between hormonal shifts and navigation strategies are less well studied. This study compared 30 peripartal women (mean age 28years) to an age-matched control group on allocentric versus egocentric navigation performance (measured in the last month of pregnancy) and gray matter volume (measured within two months after delivery). None of the women had a previous pregnancy before study participation. Relative to controls, pregnant women performed less well in the egocentric condition of the navigation task, but not the allocentric condition. A whole-brain group comparison revealed smaller left striatal volume (putamen) in the peripartal women. Across the two groups, left striatal volume was associated with superior egocentric over allocentric performance. Limited by the cross-sectional study design, the findings are a first indication that human pregnancy might be accompanied by structural brain changes in navigation-related neural systems and concomitant changes in navigation strategy. Copyright © 2016 Elsevier Inc. All rights reserved.

Navigation systems. [for interplanetary flight

NASA Technical Reports Server (NTRS)

Jordan, J. F.

1985-01-01

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.

FLASH LIDAR Based Relative Navigation

NASA Technical Reports Server (NTRS)

Brazzel, Jack; Clark, Fred; Milenkovic, Zoran

2014-01-01

Relative navigation remains the most challenging part of spacecraft rendezvous and docking. In recent years, flash LIDARs, have been increasingly selected as the go-to sensors for proximity operations and docking. Flash LIDARS are generally lighter and require less power that scanning Lidars. Flash LIDARs do not have moving parts, and they are capable of tracking multiple targets as well as generating a 3D map of a given target. However, there are some significant drawbacks of Flash Lidars that must be resolved if their use is to be of long-term significance. Overcoming the challenges of Flash LIDARs for navigation-namely, low technology readiness level, lack of historical performance data, target identification, existence of false positives, and performance of vision processing algorithms as intermediaries between the raw sensor data and the Kalman filter-requires a world-class testing facility, such as the Lockheed Martin Space Operations Simulation Center (SOSC). Ground-based testing is a critical step for maturing the next-generation flash LIDAR-based spacecraft relative navigation. This paper will focus on the tests of an integrated relative navigation system conducted at the SOSC in January 2014. The intent of the tests was to characterize and then improve the performance of relative navigation, while addressing many of the flash LIDAR challenges mentioned above. A section on navigation performance and future recommendation completes the discussion.

Concept of AHRS Algorithm Designed for Platform Independent Imu Attitude Alignment

NASA Astrophysics Data System (ADS)

Tomaszewski, Dariusz; Rapiński, Jacek; Pelc-Mieczkowska, Renata

2017-12-01

Nowadays, along with the advancement of technology one can notice the rapid development of various types of navigation systems. So far the most popular satellite navigation, is now supported by positioning results calculated with use of other measurement system. The method and manner of integration will depend directly on the destination of system being developed. To increase the frequency of readings and improve the operation of outdoor navigation systems, one will support satellite navigation systems (GPS, GLONASS ect.) with inertial navigation. Such method of navigation consists of several steps. The first stage is the determination of initial orientation of inertial measurement unit, called INS alignment. During this process, on the basis of acceleration and the angular velocity readings, values of Euler angles (pitch, roll, yaw) are calculated allowing for unambiguous orientation of the sensor coordinate system relative to external coordinate system. The following study presents the concept of AHRS (Attitude and heading reference system) algorithm, allowing to define the Euler angles.The study were conducted with the use of readings from low-cost MEMS cell phone sensors. Subsequently the results of the study were analyzed to determine the accuracy of featured algorithm. On the basis of performed experiments the legitimacy of developed algorithm was stated.

Integration of a synthetic vision system with airborne laser range scanner-based terrain referenced navigation for precision approach guidance

NASA Astrophysics Data System (ADS)

Uijt de Haag, Maarten; Campbell, Jacob; van Graas, Frank

2005-05-01

Synthetic Vision Systems (SVS) provide pilots with a virtual visual depiction of the external environment. When using SVS for aircraft precision approach guidance systems accurate positioning relative to the runway with a high level of integrity is required. Precision approach guidance systems in use today require ground-based electronic navigation components with at least one installation at each airport, and in many cases multiple installations to service approaches to all qualifying runways. A terrain-referenced approach guidance system is envisioned to provide precision guidance to an aircraft without the use of ground-based electronic navigation components installed at the airport. This autonomy makes it a good candidate for integration with an SVS. At the Ohio University Avionics Engineering Center (AEC), work has been underway in the development of such a terrain referenced navigation system. When used in conjunction with an Inertial Measurement Unit (IMU) and a high accuracy/resolution terrain database, this terrain referenced navigation system can provide navigation and guidance information to the pilot on a SVS or conventional instruments. The terrain referenced navigation system, under development at AEC, operates on similar principles as other terrain navigation systems: a ground sensing sensor (in this case an airborne laser scanner) gathers range measurements to the terrain; this data is then matched in some fashion with an onboard terrain database to find the most likely position solution and used to update an inertial sensor-based navigator. AEC's system design differs from today's common terrain navigators in its use of a high resolution terrain database (~1 meter post spacing) in conjunction with an airborne laser scanner which is capable of providing tens of thousands independent terrain elevation measurements per second with centimeter-level accuracies. When combined with data from an inertial navigator the high resolution terrain database and laser scanner system is capable of providing near meter-level horizontal and vertical position estimates. Furthermore, the system under development capitalizes on 1) The position and integrity benefits provided by the Wide Area Augmentation System (WAAS) to reduce the initial search space size and; 2) The availability of high accuracy/resolution databases. This paper presents results from flight tests where the terrain reference navigator is used to provide guidance cues for a precision approach.

Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory

NASA Technical Reports Server (NTRS)

Mitchell, J.; Johnston, A.; Howard, R.; Williamson, M.; Brewster, L.; Strack, D.; Cryan, S.

2007-01-01

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as Automated Rendezvous and Docking, AR&D). The crewed versions may also perform AR&D, possibly with a different level of automation and/or autonomy, and must also provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the CEV requirements. The relatively low technology readiness of relative navigation sensors for AR&D has been carried as one of the CEV Projects top risks. The AR&D Sensor Technology Project seeks to reduce this risk by increasing technology maturation of selected relative navigation sensor technologies through testing and simulation, and to allow the CEV Project to assess the relative navigation sensors.

Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory

NASA Technical Reports Server (NTRS)

Howard, Richard T.; Williamson, Marlin L.; Johnston, Albert S.; Brewster, Linda L.; Mitchell, Jennifer D.; Cryan, Scott P.; Strack, David; Key, Kevin

2007-01-01

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as Automated Rendezvous and Docking, (AR&D).) The crewed versions of the spacecraft may also perform AR&D, possibly with a different level of automation and/or autonomy, and must also provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the CEV requirements. The relatively low technology readiness of relative navigation sensors for AR&D has been carried as one of the CEV Projects top risks. The AR&D Sensor Technology Project seeks to reduce this risk by increasing technology maturation of selected relative navigation sensor technologies through testing and simulation, and to allow the CEV Project to assess the relative navigation sensors.

Guidewire navigation in coronary artery stenoses using a novel magnetic navigation system: first clinical experience.

PubMed

Tsuchida, Keiichi; García-García, Héctor M; van der Giessen, Willem J; McFadden, Eugène P; van der Ent, Martin; Sianos, Georgios; Meulenbrug, Hans; Ong, Andrew T L; Serruys, Patrick W

2006-03-01

The objective of this study was to investigate the efficacy of guidewire navigation across coronary artery stenoses using magnetic navigation system (MNS) versus conventional navigation. The MNS is a novel option to facilitate access to target lesions, particularly in tortuous vessels. In an experimental study using a challenging vessel phantom, magnetic-navigated guidewire passage has been reported to reduce fluoroscopy and procedure time significantly. Both magnetic and manual guidewire navigation were attempted in 21 consecutive diseased coronary arteries. The study endpoint was defined as an intraluminal wire position distal to the stenosis. Procedural success was defined as successful guidewire passage without procedural events. Procedure time, amount of contrast, fluoroscopy time, and radiation dose/area product (DAP) were evaluated. There were no procedural events related to either guidewire. Although the lesions attempted had relatively simple and straightforward characteristics, significantly shorter procedure and fluoroscopy time were observed for manual guidewire navigation compared to MNS (median, 40 vs. 120 sec, P=0.001; 38 vs. 105 sec, P=0.001, respectively). Contrast amount and DAP were higher in MNS than in conventional method (median, 13 vs. 9 ml, P=0.018; 215 vs. 73 Gym2, P=0.002, respectively). The magnetic wire did not cross in two vessels. Guidewire navigation using MNS presented a novel, safe, and feasible approach to address coronary artery lesions. Clinical studies are needed to evaluate the potential benefit of the MNS in more complex coronary lesions and tortuous anatomy. Copyright (c) 2006 Wiley-Liss, Inc.

Navigation integrity monitoring and obstacle detection for enhanced-vision systems

NASA Astrophysics Data System (ADS)

Korn, Bernd; Doehler, Hans-Ullrich; Hecker, Peter

2001-08-01

Typically, Enhanced Vision (EV) systems consist of two main parts, sensor vision and synthetic vision. Synthetic vision usually generates a virtual out-the-window view using databases and accurate navigation data, e. g. provided by differential GPS (DGPS). The reliability of the synthetic vision highly depends on both, the accuracy of the used database and the integrity of the navigation data. But especially in GPS based systems, the integrity of the navigation can't be guaranteed. Furthermore, only objects that are stored in the database can be displayed to the pilot. Consequently, unexpected obstacles are invisible and this might cause severe problems. Therefore, additional information has to be extracted from sensor data to overcome these problems. In particular, the sensor data analysis has to identify obstacles and has to monitor the integrity of databases and navigation. Furthermore, if a lack of integrity arises, navigation data, e.g. the relative position of runway and aircraft, has to be extracted directly from the sensor data. The main contribution of this paper is about the realization of these three sensor data analysis tasks within our EV system, which uses the HiVision 35 GHz MMW radar of EADS, Ulm as the primary EV sensor. For the integrity monitoring, objects extracted from radar images are registered with both database objects and objects (e. g. other aircrafts) transmitted via data link. This results in a classification into known and unknown radar image objects and consequently, in a validation of the integrity of database and navigation. Furthermore, special runway structures are searched for in the radar image where they should appear. The outcome of this runway check contributes to the integrity analysis, too. Concurrent to this investigation a radar image based navigation is performed without using neither precision navigation nor detailed database information to determine the aircraft's position relative to the runway. The performance of our approach is demonstrated with real data acquired during extensive flight tests to several airports in Northern Germany.

DIY-style GIS service in mobile navigation system integrated with web and wireless GIS

NASA Astrophysics Data System (ADS)

Yan, Yongbin; Wu, Jianping; Fan, Caiyou; Wang, Minqi; Dai, Sheng

2007-06-01

Mobile navigation system based on handheld device can not only provide basic GIS services, but also enable these GIS services to be provided without location limit, to be more instantly interacted between users and devices. However, we still see that most navigation systems have common defects on user experience like limited map format, few map resources, and unable location share. To overcome the above defects, we propose DIY-style GIS service which provide users a more free software environment and allow uses to customize their GIS services. These services include defining geographical coordinate system of maps which helps to hugely enlarge the map source, editing vector feature, related property information and hotlink images, customizing covered area of download map via General Packet Radio Service (GPRS), and sharing users' location information via SMS (Short Message Service) which establishes the communication between users who needs GIS services. The paper introduces the integration of web and wireless GIS service in a mobile navigation system and presents an implementation sample of a DIY-Style GIS service in a mobile navigation system.

Embedded Relative Navigation Sensor Fusion Algorithms for Autonomous Rendezvous and Docking Missions

NASA Technical Reports Server (NTRS)

DeKock, Brandon K.; Betts, Kevin M.; McDuffie, James H.; Dreas, Christine B.

2008-01-01

bd Systems (a subsidiary of SAIC) has developed a suite of embedded relative navigation sensor fusion algorithms to enable NASA autonomous rendezvous and docking (AR&D) missions. Translational and rotational Extended Kalman Filters (EKFs) were developed for integrating measurements based on the vehicles' orbital mechanics and high-fidelity sensor error models and provide a solution with increased accuracy and robustness relative to any single relative navigation sensor. The filters were tested tinough stand-alone covariance analysis, closed-loop testing with a high-fidelity multi-body orbital simulation, and hardware-in-the-loop (HWIL) testing in the Marshall Space Flight Center (MSFC) Flight Robotics Laboratory (FRL).

Clinical performance of dental fiberscope image guided system for endodontic treatment.

PubMed

Yamazaki, Yasushi; Ogawa, Takumi; Shigeta, Yuko; Ikawa, Tomoko; Kasama, Shintaro; Hattori, Asaki; Suzuki, Naoki; Yamamoto, Takatsugu; Ozawa, Toshiko; Arai, Takashi

2011-01-01

We developed a dental fiberscope that can be navigated. As a result we are able to better grasp the device position relative to the teeth, aiming at the lesion more precisely. However, the device position and the precise target setting were difficult to consistently ascertain. The aim of this study is to navigate the position of tip of the dental fiberscope fiber in the root canal with our navigation system. A 3D tooth model was made from the raw dental CT data. In addition, the optical position of the measurement device, OPTOTRAK system was used for registration of the 3D model and actual teeth position and to chase the scope movement. We developed exclusive software to unify information. We were subsequently able to precisely indicate the relation of the position between the device and the teeth on the 3D model in the monitor. This allowed us to aim at the lesion more precisely, as the revised endoscopic image matched the 3D model. The application of this endoscopic navigation system could increase the success rate for root canal treatments with recalcitrant lesion.

Navigation system for minimally invasive esophagectomy: experimental study in a porcine model.

PubMed

Nickel, Felix; Kenngott, Hannes G; Neuhaus, Jochen; Sommer, Christof M; Gehrig, Tobias; Kolb, Armin; Gondan, Matthias; Radeleff, Boris A; Schaible, Anja; Meinzer, Hans-Peter; Gutt, Carsten N; Müller-Stich, Beat-Peter

2013-10-01

Navigation systems potentially facilitate minimally invasive esophagectomy and improve patient outcome by improving intraoperative orientation, position estimation of instruments, and identification of lymph nodes and resection margins. The authors' self-developed navigation system is highly accurate in static environments. This study aimed to test the overall accuracy of the navigation system in a realistic operating room scenario and to identify the different sources of error altering accuracy. To simulate a realistic environment, a porcine model (n = 5) was used with endoscopic clips in the esophagus as navigation targets. Computed tomography imaging was followed by image segmentation and target definition with the medical imaging interaction toolkit software. Optical tracking was used for registration and localization of animals and navigation instruments. Intraoperatively, the instrument was displayed relative to segmented organs in real time. The target registration error (TRE) of the navigation system was defined as the distance between the target and the navigation instrument tip. The TRE was measured on skin targets with the animal in the 0° supine and 25° anti-Trendelenburg position and on the esophagus during laparoscopic transhiatal preparation. On skin targets, the TRE was significantly higher in the 25° position, at 14.6 ± 2.7 mm, compared with the 0° position, at 3.2 ± 1.3 mm. The TRE on the esophagus was 11.2 ± 2.4 mm. The main source of error was soft tissue deformation caused by intraoperative positioning, pneumoperitoneum, surgical manipulation, and tissue dissection. The navigation system obtained acceptable accuracy with a minimally invasive transhiatal approach to the esophagus in a realistic experimental model. Thus the system has the potential to improve intraoperative orientation, identification of lymph nodes and adequate resection margins, and visualization of risk structures. Compensation methods for soft tissue deformation may lead to an even more accurate navigation system in the future.

Orion Exploration Flight Test-1 Post-Flight Navigation Performance Assessment Relative to the Best Estimated Trajectory

NASA Technical Reports Server (NTRS)

Gay, Robert S.; Holt, Greg N.; Zanetti, Renato

2016-01-01

This paper details the post-flight navigation performance assessment of the Orion Exploration Flight Test-1 (EFT-1). Results of each flight phase are presented: Ground Align, Ascent, Orbit, and Entry Descent and Landing. This study examines the on-board Kalman Filter uncertainty along with state deviations relative to the Best Estimated Trajectory (BET). Overall the results show that the Orion Navigation System performed as well or better than expected. Specifically, the Global Positioning System (GPS) measurement availability was significantly better than anticipated at high altitudes. In addition, attitude estimation via processing GPS measurements along with Inertial Measurement Unit (IMU) data performed very well and maintained good attitude throughout the mission.

Single-Frequency GPS Relative Navigation in a High Ionosphere Orbital Environment

NASA Technical Reports Server (NTRS)

Conrad, Patrick R.; Naasz, Bo J.

2007-01-01

The Global Positioning System (GPS) provides a convenient source for space vehicle relative navigation measurements, especially for low Earth orbit formation flying and autonomous rendezvous mission concepts. For single-frequency GPS receivers, ionospheric path delay can be a significant error source if not properly mitigated. In particular, ionospheric effects are known to cause significant radial position error bias and add dramatically to relative state estimation error if the onboard navigation software does not force the use of measurements from common or shared GPS space vehicles. Results from GPS navigation simulations are presented for a pair of space vehicles flying in formation and using GPS pseudorange measurements to perform absolute and relative orbit determination. With careful measurement selection techniques relative state estimation accuracy to less than 20 cm with standard GPS pseudorange processing and less than 10 cm with single-differenced pseudorange processing is shown.

Earth-Referenced Aircraft Navigation and Surveillance Analysis

DOT National Transportation Integrated Search

2016-06-01

This document addresses a basic function of aircraft (and other vehicle) surveillance and navi-gation systems analyses quantifying the geometric relationship of two or more locations relative to each other and to the earth. Here, geometry means d...

Navigation in the electronic health record: A review of the safety and usability literature.

PubMed

Roman, Lisette C; Ancker, Jessica S; Johnson, Stephen B; Senathirajah, Yalini

2017-03-01

Inefficient navigation in electronic health records has been shown to increase users' cognitive load, which may increase potential for errors, reduce efficiency, and increase fatigue. However, navigation has received insufficient recognition and attention in the electronic health record (EHR) literature as an independent construct and contributor to overall usability. Our aims in this literature review were to (1) assess the prevalence of navigation-related topics within the EHR usability and safety research literature, (2) categorize types of navigation actions within the EHR, (3) capture relationships between these navigation actions and usability principles, and (4) collect terms and concepts related to EHR navigation. Our goal was to improve access to navigation-related research in usability. We applied scoping literature review search methods with the assistance of a reference librarian to identify articles published since 1996 that reported evaluation of the usability or safety of an EHR user interface via user test, analytic methods, or inspection methods. The 4336 references collected from MEDLINE, EMBASE, Engineering Village, and expert referrals were de-duplicated and screened for relevance, and navigation-related concepts were abstracted from the 21 articles eligible for review using a standard abstraction form. Of the 21 eligible articles, 20 (95%) mentioned navigation in results and discussion of usability evaluations. Navigation between pages of the EHR was the more frequently documented type of navigation (86%) compared to navigation within a single page (14%). Navigation actions (e.g., scrolling through a medication list) were frequently linked to specific usability heuristic violations, among which flexibility and efficiency of use, recognition rather than recall, and error prevention were most common. Discussion of navigation was prevalent in results across all types of evaluation methods among the articles reviewed. Navigating between multiple screens was frequently identified as a usability barrier. The lack of standard terminology created some challenges to identifying and comparing articles. We observed that usability researchers are frequently capturing navigation-related issues even in articles that did not explicitly state navigation as a focus. Capturing and synthesizing the literature on navigation is challenging because of the lack of uniform vocabulary. Navigation is a potential target for normative recommendations for improved interaction design for safer systems. Future research in this domain, including development of normative recommendations for usability design and evaluation, will be facilitated by development of a standard terminology for describing EHR navigation. Copyright © 2017 Elsevier Inc. All rights reserved.

Polar Cooperative Navigation Algorithm for Multi-Unmanned Underwater Vehicles Considering Communication Delays.

PubMed

Yan, Zheping; Wang, Lu; Wang, Tongda; Yang, Zewen; Chen, Tao; Xu, Jian

2018-03-30

To solve the navigation accuracy problems of multi-Unmanned Underwater Vehicles (multi-UUVs) in the polar region, a polar cooperative navigation algorithm for multi-UUVs considering communication delays is proposed in this paper. UUVs are important pieces of equipment in ocean engineering for marine development. For UUVs to complete missions, precise navigation is necessary. It is difficult for UUVs to establish true headings because of the rapid convergence of Earth meridians and the severe polar environment. Based on the polar grid navigation algorithm, UUV navigation in the polar region can be accomplished with the Strapdown Inertial Navigation System (SINS) in the grid frame. To save costs, a leader-follower type of system is introduced in this paper. The leader UUV helps the follower UUVs to achieve high navigation accuracy. Follower UUVs correct their own states based on the information sent by the leader UUV and the relative position measured by ultra-short baseline (USBL) acoustic positioning. The underwater acoustic communication delay is quantized by the model. In this paper, considering underwater acoustic communication delay, the conventional adaptive Kalman filter (AKF) is modified to adapt to polar cooperative navigation. The results demonstrate that the polar cooperative navigation algorithm for multi-UUVs that considers communication delays can effectively navigate the sailing of multi-UUVs in the polar region.

Polar Cooperative Navigation Algorithm for Multi-Unmanned Underwater Vehicles Considering Communication Delays

PubMed Central

Yan, Zheping; Wang, Lu; Wang, Tongda; Yang, Zewen; Chen, Tao; Xu, Jian

2018-01-01

To solve the navigation accuracy problems of multi-Unmanned Underwater Vehicles (multi-UUVs) in the polar region, a polar cooperative navigation algorithm for multi-UUVs considering communication delays is proposed in this paper. UUVs are important pieces of equipment in ocean engineering for marine development. For UUVs to complete missions, precise navigation is necessary. It is difficult for UUVs to establish true headings because of the rapid convergence of Earth meridians and the severe polar environment. Based on the polar grid navigation algorithm, UUV navigation in the polar region can be accomplished with the Strapdown Inertial Navigation System (SINS) in the grid frame. To save costs, a leader-follower type of system is introduced in this paper. The leader UUV helps the follower UUVs to achieve high navigation accuracy. Follower UUVs correct their own states based on the information sent by the leader UUV and the relative position measured by ultra-short baseline (USBL) acoustic positioning. The underwater acoustic communication delay is quantized by the model. In this paper, considering underwater acoustic communication delay, the conventional adaptive Kalman filter (AKF) is modified to adapt to polar cooperative navigation. The results demonstrate that the polar cooperative navigation algorithm for multi-UUVs that considers communication delays can effectively navigate the sailing of multi-UUVs in the polar region. PMID:29601537

Soft tissue navigation for laparoscopic prostatectomy: evaluation of camera pose estimation for enhanced visualization

NASA Astrophysics Data System (ADS)

Baumhauer, M.; Simpfendörfer, T.; Schwarz, R.; Seitel, M.; Müller-Stich, B. P.; Gutt, C. N.; Rassweiler, J.; Meinzer, H.-P.; Wolf, I.

2007-03-01

We introduce a novel navigation system to support minimally invasive prostate surgery. The system utilizes transrectal ultrasonography (TRUS) and needle-shaped navigation aids to visualize hidden structures via Augmented Reality. During the intervention, the navigation aids are segmented once from a 3D TRUS dataset and subsequently tracked by the endoscope camera. Camera Pose Estimation methods directly determine position and orientation of the camera in relation to the navigation aids. Accordingly, our system does not require any external tracking device for registration of endoscope camera and ultrasonography probe. In addition to a preoperative planning step in which the navigation targets are defined, the procedure consists of two main steps which are carried out during the intervention: First, the preoperatively prepared planning data is registered with an intraoperatively acquired 3D TRUS dataset and the segmented navigation aids. Second, the navigation aids are continuously tracked by the endoscope camera. The camera's pose can thereby be derived and relevant medical structures can be superimposed on the video image. This paper focuses on the latter step. We have implemented several promising real-time algorithms and incorporated them into the Open Source Toolkit MITK (www.mitk.org). Furthermore, we have evaluated them for minimally invasive surgery (MIS) navigation scenarios. For this purpose, a virtual evaluation environment has been developed, which allows for the simulation of navigation targets and navigation aids, including their measurement errors. Besides evaluating the accuracy of the computed pose, we have analyzed the impact of an inaccurate pose and the resulting displacement of navigation targets in Augmented Reality.

Robotic platform for traveling on vertical piping network

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

Nance, Thomas A; Vrettos, Nick J; Krementz, Daniel

This invention relates generally to robotic systems and is specifically designed for a robotic system that can navigate vertical pipes within a waste tank or similar environment. The robotic system allows a process for sampling, cleaning, inspecting and removing waste around vertical pipes by supplying a robotic platform that uses the vertical pipes to support and navigate the platform above waste material contained in the tank.

The First Result of Relative Positioning and Velocity Estimation Based on CAPS

PubMed Central

Zhao, Jiaojiao; Ge, Jian; Wang, Liang; Wang, Ningbo; Zhou, Kai; Yuan, Hong

2018-01-01

The Chinese Area Positioning System (CAPS) is a new positioning system developed by the Chinese Academy of Sciences based on the communication satellites in geosynchronous orbit. The CAPS has been regarded as a pilot system to test the new technology for the design, construction and update of the BeiDou Navigation Satellite System (BDS). The system structure of CAPS, including the space, ground control station and user segments, is almost like the traditional Global Navigation Satellite Systems (GNSSs), but with the clock on the ground, the navigation signal in C waveband, and different principles of operation. The major difference is that the CAPS navigation signal is first generated at the ground control station, before being transmitted to the satellite in orbit and finally forwarded by the communication satellite transponder to the user. This design moves the clock from the satellite in orbit to the ground. The clock error can therefore be easily controlled and mitigated to improve the positioning accuracy. This paper will present the performance of CAPS-based relative positioning and velocity estimation as assessed in Beijing, China. The numerical results show that, (1) the accuracies of relative positioning, using only code measurements, are 1.25 and 1.8 m in the horizontal and vertical components, respectively; (2) meanwhile, they are about 2.83 and 3.15 cm in static mode and 6.31 and 10.78 cm in kinematic mode, respectively, when using the carrier-phase measurements with ambiguities fixed; and (3) the accuracy of the velocity estimation is about 0.04 and 0.11 m/s in static and kinematic modes, respectively. These results indicate the potential application of CAPS for high-precision positioning and velocity estimation and the availability of a new navigation mode based on communication satellites. PMID:29757204

BOREAS Level-0 C-130 Navigation Data

NASA Technical Reports Server (NTRS)

Strub, Richard; Newcomer, Jeffrey A.; Domingues, Roseanne; Hall, Forrest G. (Editor)

2000-01-01

The level-0 C-130 navigation data files contain aircraft attitude and position information acquired during the digital image and photographic data collection missions over the BOReal Ecosystem-Atmosphere Study (BOREAS) study areas. Various portions of the navigation data were collected at 1, 10, and 30 Hz. The level-0 C-130 navigation data collected for BOREAS in 1994 were improved over previous years in that the C-130 onboard navigation system was upgraded to output inertial navigation parameters every 1/30th of a second (i.e., 30 Hz). This upgrade was encouraged by users of the aircraft scanner data with the hope of improving the relative geometric positioning of the collected images.

Guidance and Navigation Requirements for Unmanned Flyby and Swingby Missions to the Outer Planets. Volume 3; Low Thrust Missions, Phase B

NASA Technical Reports Server (NTRS)

1970-01-01

The guidance and navigation requirements for unmanned missions to the outer planets, assuming constant, low thrust, ion propulsion are discussed. The navigational capability of the ground based Deep Space Network is compared to the improvements in navigational capability brought about by the addition of guidance and navigation related onboard sensors. Relevant onboard sensors include: (1) the optical onboard navigation sensor, (2) the attitude reference sensors, and (3) highly sensitive accelerometers. The totally ground based, and the combination ground based and onboard sensor systems are compared by means of the estimated errors in target planet ephemeris, and the spacecraft position with respect to the planet.

Real-time Terrain Relative Navigation Test Results from a Relevant Environment for Mars Landing

NASA Technical Reports Server (NTRS)

Johnson, Andrew E.; Cheng, Yang; Montgomery, James; Trawny, Nikolas; Tweddle, Brent; Zheng, Jason

2015-01-01

Terrain Relative Navigation (TRN) is an on-board GN&C function that generates a position estimate of a spacecraft relative to a map of a planetary surface. When coupled with a divert, the position estimate enables access to more challenging landing sites through pin-point landing or large hazard avoidance. The Lander Vision System (LVS) is a smart sensor system that performs terrain relative navigation by matching descent camera imagery to a map of the landing site and then fusing this with inertial measurements to obtain high rate map relative position, velocity and attitude estimates. A prototype of the LVS was recently tested in a helicopter field test over Mars analog terrain at altitudes representative of Mars Entry Descent and Landing conditions. TRN ran in real-time on the LVS during the flights without human intervention or tuning. The system was able to compute estimates accurate to 40m (3 sigma) in 10 seconds on a flight like processing system. This paper describes the Mars operational test space definition, how the field test was designed to cover that operational envelope, the resulting TRN performance across the envelope and an assessment of test space coverage.

Satellite-aided coastal zone monitoring and vessel traffic system

NASA Technical Reports Server (NTRS)

Baker, J. L.

1981-01-01

The development and demonstration of a coastal zone monitoring and vessel traffic system is described. This technique uses a LORAN-C navigational system and relays signals via the ATS-3 satellite to a computer driven color video display for real time control. Multi-use applications of the system to search and rescue operations, coastal zone management and marine safety are described. It is emphasized that among the advantages of the system are: its unlimited range; compatibility with existing navigation systems; and relatively inexpensive cost.

Space Segment (SS) and the Navigation User Segment (US) Interface Control Document (ICD)

DOT National Transportation Integrated Search

1993-10-10

This Interface Control Document (ICD) defines the requirements related to the interface between the Space Segment (SS) of the Global Positioning System (GPS) and the Navigation Users Segment of the GPS. 2880k, 154p.

Design and testing of a multi-sensor pedestrian location and navigation platform.

PubMed

Morrison, Aiden; Renaudin, Valérie; Bancroft, Jared B; Lachapelle, Gérard

2012-01-01

Navigation and location technologies are continually advancing, allowing ever higher accuracies and operation under ever more challenging conditions. The development of such technologies requires the rapid evaluation of a large number of sensors and related utilization strategies. The integration of Global Navigation Satellite Systems (GNSSs) such as the Global Positioning System (GPS) with accelerometers, gyros, barometers, magnetometers and other sensors is allowing for novel applications, but is hindered by the difficulties to test and compare integrated solutions using multiple sensor sets. In order to achieve compatibility and flexibility in terms of multiple sensors, an advanced adaptable platform is required. This paper describes the design and testing of the NavCube, a multi-sensor navigation, location and timing platform. The system provides a research tool for pedestrian navigation, location and body motion analysis in an unobtrusive form factor that enables in situ data collections with minimal gait and posture impact. Testing and examples of applications of the NavCube are provided.

Integration of radar altimeter, precision navigation, and digital terrain data for low-altitude flight

NASA Technical Reports Server (NTRS)

Zelenka, Richard E.

1992-01-01

Avionic systems that depend on digitized terrain elevation data for guidance generation or navigational reference require accurate absolute and relative distance measurements to the terrain, especially as they approach lower altitudes. This is particularly exacting in low-altitude helicopter missions, where aggressive terrain hugging maneuvers create minimal horizontal and vertical clearances and demand precise terrain positioning. Sole reliance on airborne precision navigation and stored terrain elevation data for above-ground-level (AGL) positioning severely limits the operational altitude of such systems. A Kalman filter is presented which blends radar altimeter returns, precision navigation, and stored terrain elevation data for AGL positioning. The filter is evaluated using low-altitude helicopter flight test data acquired over moderately rugged terrain. The proposed Kalman filter is found to remove large disparities in predicted AGL altitude (i.e., from airborne navigation and terrain elevation data) in the presence of measurement anomalies and dropouts. Previous work suggested a minimum clearance altitude of 220 ft AGL for a near-terrain guidance system; integration of a radar altimeter allows for operation of that system below 50 ft, subject to obstacle-avoidance limitations.

Cloud Absorption Radiometer Autonomous Navigation System - CANS

NASA Technical Reports Server (NTRS)

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

2013-01-01

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.

COBALT CoOperative Blending of Autonomous Landing Technology

NASA Technical Reports Server (NTRS)

Carson, John M. III; Restrepo, Carolina I.; Robertson, Edward A.; Seubert, Carl R.; Amzajerdian, Farzin

2016-01-01

COBALT is a terrestrial test platform for development and maturation of GN&C (Guidance, Navigation and Control) technologies for PL&HA (Precision Landing and Hazard Avoidance). The project is developing a third generation, Langley Navigation Doppler Lidar (NDL) for ultra-precise velocity and range measurements, which will be integrated and tested with the JPL Lander Vision System (LVS) for Terrain Relative Navigation (TRN) position estimates. These technologies together provide navigation that enables controlled precision landing. The COBALT hardware will be integrated in 2017 into the GN&C subsystem of the Xodiac rocket-propulsive Vertical Test Bed (VTB) developed by Masten Space Systems (MSS), and two terrestrial flight campaigns will be conducted: one open-loop (i.e., passive) and one closed-loop (i.e., active).

SURVIVORSHIP NAVIGATION OUTCOME MEASURES: A report from the ACS Patient Navigation Working Group on Survivorship Navigation

PubMed Central

Pratt-Chapman, Mandi; Simon, Melissa A.; Patterson, Angela; Risendal, Betsy C.; Patierno, Steven

2013-01-01

Survivorship navigation is a relatively new concept in the field of patient navigation, but an important one. This paper highlights the essential functions of the survivorship navigator and defines core outcomes and measures for navigation in the survivorship period. Barriers to access to care experienced by patients during active cancer treatment can continue into the post-treatment period, affecting quality follow-up care for survivors. These barriers to care can be particularly acute for non-English speakers, immigrants, the uninsured, the underinsured and other vulnerable populations. The survivorship navigator can help reduce barriers and facilitate access to survivorship care and services through communication and information exchange for patients. Survivorship navigation may improve appropriate health care utilization through education and care coordination, potentially improving health outcomes and quality of life of survivors while reducing cost to the health care system. Survivorship navigators can also educate survivors on how to improve their overall wellness, thereby directly impacting the health of a growing population of cancer survivors. PMID:21780092

Navigation through unknown and dynamic open spaces using topological notions

NASA Astrophysics Data System (ADS)

Miguel-Tomé, Sergio

2018-04-01

Until now, most algorithms used for navigation have had the purpose of directing system towards one point in space. However, humans communicate tasks by specifying spatial relations among elements or places. In addition, the environments in which humans develop their activities are extremely dynamic. The only option that allows for successful navigation in dynamic and unknown environments is making real-time decisions. Therefore, robots capable of collaborating closely with human beings must be able to make decisions based on the local information registered by the sensors and interpret and express spatial relations. Furthermore, when one person is asked to perform a task in an environment, this task is communicated given a category of goals so the person does not need to be supervised. Thus, two problems appear when one wants to create multifunctional robots: how to navigate in dynamic and unknown environments using spatial relations and how to accomplish this without supervision. In this article, a new architecture to address the two cited problems is presented, called the topological qualitative navigation architecture. In previous works, a qualitative heuristic called the heuristic of topological qualitative semantics (HTQS) has been developed to establish and identify spatial relations. However, that heuristic only allows for establishing one spatial relation with a specific object. In contrast, navigation requires a temporal sequence of goals with different objects. The new architecture attains continuous generation of goals and resolves them using HTQS. Thus, the new architecture achieves autonomous navigation in dynamic or unknown open environments.

Patterns of task and network actions performed by navigators to facilitate cancer care.

PubMed

Clark, Jack A; Parker, Victoria A; Battaglia, Tracy A; Freund, Karen M

2014-01-01

Patient navigation is a widely implemented intervention to facilitate access to care and reduce disparities in cancer care, but the activities of navigators are not well characterized. The aim of this study is to describe what patient navigators actually do and explore patterns of activity that clarify the roles they perform in facilitating cancer care. We conducted field observations of nine patient navigation programs operating in diverse health settings of the national patient navigation research program, including 34 patient navigators, each observed an average of four times. Trained observers used a structured observation protocol to code as they recorded navigator actions and write qualitative field notes capturing all activities in 15-minute intervals during observations ranging from 2 to 7 hours; yielding a total of 133 observations. Rates of coded activity were analyzed using numerical cluster analysis of identified patterns, informed by qualitative analysis of field notes. Six distinct patterns of navigator activity were identified, which differed most relative to how much time navigators spent directly interacting with patients and how much time they spent dealing with medical records and documentation tasks. Navigator actions reveal a complex set of roles in which navigators both provide the direct help to patients denoted by their title and also carry out a variety of actions that function to keep the health system operating smoothly. Working to navigate patients through complex health services entails working to repair the persistent challenges of health services that can render them inhospitable to patients. The organizations that deploy navigators might learn from navigators' efforts and explore alternative approaches, structures, or systems of care in addressing both the barriers patients face and the complex solutions navigators create in helping patients.

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

NASA Technical Reports Server (NTRS)

Psiaki, Mark L.

2003-01-01

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.

Integrated communications and optical navigation system

NASA Astrophysics Data System (ADS)

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

2013-12-01

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.

Vision-Aided Context-Aware Framework for Personal Navigation Services

NASA Astrophysics Data System (ADS)

Saeedi, S.; Moussa, A.; El-Sheimy, N., , Dr.

2012-07-01

The ubiquity of mobile devices (such as smartphones and tablet-PCs) has encouraged the use of location-based services (LBS) that are relevant to the current location and context of a mobile user. The main challenge of LBS is to find a pervasive and accurate personal navigation system (PNS) in different situations of a mobile user. In this paper, we propose a method of personal navigation for pedestrians that allows a user to freely move in outdoor environments. This system aims at detection of the context information which is useful for improving personal navigation. The context information for a PNS consists of user activity modes (e.g. walking, stationary, driving, and etc.) and the mobile device orientation and placement with respect to the user. After detecting the context information, a low-cost integrated positioning algorithm has been employed to estimate pedestrian navigation parameters. The method is based on the integration of the relative user's motion (changes of velocity and heading angle) estimation based on the video image matching and absolute position information provided by GPS. A Kalman filter (KF) has been used to improve the navigation solution when the user is walking and the phone is in his/her hand. The Experimental results demonstrate the capabilities of this method for outdoor personal navigation systems.

ALHAT COBALT: CoOperative Blending of Autonomous Landing Technology

NASA Technical Reports Server (NTRS)

Carson, John M.

2015-01-01

The COBALT project is a flight demonstration of two NASA ALHAT (Autonomous precision Landing and Hazard Avoidance Technology) capabilities that are key for future robotic or human landing GN&C (Guidance, Navigation and Control) systems. The COBALT payload integrates the Navigation Doppler Lidar (NDL) for ultraprecise velocity and range measurements with the Lander Vision System (LVS) for Terrain Relative Navigation (TRN) position estimates. Terrestrial flight tests of the COBALT payload in an open-loop and closed-loop GN&C configuration will be conducted onboard a commercial, rocket-propulsive Vertical Test Bed (VTB) at a test range in Mojave, CA.

A Feasibility Analysis of Land-Based SINS/GNSS Gravimetry for Groundwater Resource Detection in Taiwan

PubMed Central

Chiang, Kai-Wei; Lin, Cheng-An; Kuo, Chung-Yen

2015-01-01

The integration of the Strapdown Inertial Navigation System and Global Navigation Satellite System (SINS/GNSS) has been implemented for land-based gravimetry and has been proven to perform well in estimating gravity. Based on the mGal-level gravimetry results, this research aims to construct and develop a land-based SINS/GNSS gravimetry device containing a navigation-grade Inertial Measurement Unit. This research also presents a feasibility analysis for groundwater resource detection. A preliminary comparison of the kinematic velocities and accelerations using multi-combination of GNSS data including Global Positioning System, Global Navigation Satellite System, and BeiDou Navigation Satellite System, indicates that three-system observations performed better than two-system data in the computation. A comparison of gravity derived from SINS/GNSS and measured using a relative gravimeter also shows that both agree reasonably well with a mean difference of 2.30 mGal. The mean difference between repeat measurements of gravity disturbance using SINS/GNSS is 2.46 mGal with a standard deviation of 1.32 mGal. The gravity variation because of the groundwater at Pingtung Plain, Taiwan could reach 2.72 mGal. Hence, the developed land-based SINS/GNSS gravimetry can sufficiently and effectively detect groundwater resources. PMID:26426019

A Feasibility Analysis of Land-Based SINS/GNSS Gravimetry for Groundwater Resource Detection in Taiwan.

PubMed

Chiang, Kai-Wei; Lin, Cheng-An; Kuo, Chung-Yen

2015-09-29

The integration of the Strapdown Inertial Navigation System and Global Navigation Satellite System (SINS/GNSS) has been implemented for land-based gravimetry and has been proven to perform well in estimating gravity. Based on the mGal-level gravimetry results, this research aims to construct and develop a land-based SINS/GNSS gravimetry device containing a navigation-grade Inertial Measurement Unit. This research also presents a feasibility analysis for groundwater resource detection. A preliminary comparison of the kinematic velocities and accelerations using multi-combination of GNSS data including Global Positioning System, Global Navigation Satellite System, and BeiDou Navigation Satellite System, indicates that three-system observations performed better than two-system data in the computation. A comparison of gravity derived from SINS/GNSS and measured using a relative gravimeter also shows that both agree reasonably well with a mean difference of 2.30 mGal. The mean difference between repeat measurements of gravity disturbance using SINS/GNSS is 2.46 mGal with a standard deviation of 1.32 mGal. The gravity variation because of the groundwater at Pingtung Plain, Taiwan could reach 2.72 mGal. Hence, the developed land-based SINS/GNSS gravimetry can sufficiently and effectively detect groundwater resources.

Investigation of Air Transportation Technology at Ohio University, 1989-1990

NASA Technical Reports Server (NTRS)

Lilley, Robert W.

1990-01-01

The activities of the participants in the Joint University Program (JUP) at Ohio University are briefly surveyed. During 1989 to 1990, five topics received emphasis. A spectrum-efficient weather data uplink system was designed, constructed, and flight tested. An integrated Global Positioning System/Inertial Navigation System (GPS/INS) study continued, utilizing the Redundant strapdown Inertial Measurement Unit (IMU) on loan from NASA. The Ridge Regression theory was refined and applied to air navigation scenarios. System Identification theory was applied to GPS data to point the way to better understanding of the effects of Selective Availability on civilian users of this navigation system. An analysis of thought-related (electroencephalographic) signals for application to control of computer systems that could have significance in aiding paraplegics or for hands-off systems control in industrial or air traffic control areas was carried out.

Navigation studies based on the ubiquitous positioning technologies

NASA Astrophysics Data System (ADS)

Ye, Lei; Mi, Weijie; Wang, Defeng

2007-11-01

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

Method and apparatus for relative navigation using reflected GPS signals

NASA Technical Reports Server (NTRS)

Cohen, Ian R. (Inventor); Boegner, Jr., Gregory J. (Inventor)

2010-01-01

A method and system to passively navigate an orbiting moving body towards an orbiting target using reflected GPS signals. A pair of antennas is employed to receive both direct signals from a plurality of GPS satellites and a second antenna to receive GPS signals reflected off an orbiting target. The direct and reflected signals are processed and compared to determine the relative distance and position of the orbiting moving body relative to the orbiting target.

33 CFR 62.51 - Western Rivers Marking System.

Code of Federal Regulations, 2012 CFR

2012-07-01

....51 Section 62.51 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.51 Western Rivers Marking System. (a) A variation of the standard U.S. aids to navigation system described above is employed...

33 CFR 62.51 - Western Rivers Marking System.

Code of Federal Regulations, 2013 CFR

2013-07-01

....51 Section 62.51 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.51 Western Rivers Marking System. (a) A variation of the standard U.S. aids to navigation system described above is employed...

33 CFR 62.51 - Western Rivers Marking System.

Code of Federal Regulations, 2014 CFR

2014-07-01

....51 Section 62.51 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.51 Western Rivers Marking System. (a) A variation of the standard U.S. aids to navigation system described above is employed...

33 CFR 157.134 - Cargo tank drainage.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Cargo tank drainage. 157.134...) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.134 Cargo tank...

33 CFR 157.124 - COW tank washing machines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false COW tank washing machines. 157... (CONTINUED) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157...

33 CFR 157.140 - Tank vessel inspections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Tank vessel inspections. 157.140...) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Inspections § 157.140 Tank vessel inspections. (a) Before...

33 CFR 157.134 - Cargo tank drainage.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Cargo tank drainage. 157.134...) POLLUTION RULES FOR THE PROTECTION OF THE MARINE ENVIRONMENT RELATING TO TANK VESSELS CARRYING OIL IN BULK Crude Oil Washing (COW) System on Tank Vessels Design, Equipment, and Installation § 157.134 Cargo tank...

Relative receiver autonomous integrity monitoring for future GNSS-based aircraft navigation

NASA Astrophysics Data System (ADS)

Gratton, Livio Rafael

The Global Positioning System (GPS) has enabled reliable, safe, and practical aircraft positioning for en-route and non-precision phases of flight for more than a decade. Intense research is currently devoted to extending the use of Global Navigation Satellite Systems (GNSS), including GPS, to precision approach and landing operations. In this context, this work is focused on the development, analysis, and verification of the concept of Relative Receiver Autonomous Integrity Monitoring (RRAIM) and its potential applications to precision approach navigation. RRAIM fault detection algorithms are developed, and associated mathematical bounds on position error are derived. These are investigated as possible solutions to some current key challenges in precision approach navigation, discussed below. Augmentation systems serving continent-size areas (like the Wide Area Augmentation System or WAAS) allow certain precision approach operations within the covered region. More and better satellites, with dual frequency capabilities, are expected to be in orbit in the mid-term future, which will potentially allow WAAS-like capabilities worldwide with a sparse ground station network. Two main challenges in achieving this goal are (1) ensuring that navigation fault detection functions are fast enough to alert worldwide users of hazardously misleading information, and (2) minimizing situations in which navigation is unavailable because the user's local satellite geometry is insufficient for safe position estimation. Local augmentation systems (implemented at individual airports, like the Local Area Augmentation System or LAAS) have the potential to allow precision approach and landing operations by providing precise corrections to user-satellite range measurements. An exception to these capabilities arises during ionospheric storms (caused by solar activity), when hazardous situations can exist with residual range errors several orders of magnitudes higher than nominal. Until dual frequency civil GPS signals are available, the ability to provide integrity during ionospheric storms, without excessive loss of availability is a major challenge. For all users, with or without augmentation, some situations cause short duration losses of satellites in view. Two examples are aircraft banking during turns and ionospheric scintillation. The loss of range signals can translate into gaps in good satellite geometry, and the resulting challenge is to ensure navigation continuity by bridging these gaps, while simultaneously maintaining high integrity. It is shown that the RRAIM methods developed in this research can be applied to mitigate each of these obstacles to safe and reliable precision aircraft navigation.

Precise laser gyroscope for autonomous inertial navigation

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

Kuznetsov, A G; Molchanov, A V; Izmailov, E A

2015-01-31

Requirements to gyroscopes of strapdown inertial navigation systems for aircraft application are formulated. The construction of a ring helium – neon laser designed for autonomous navigation is described. The processes that determine the laser service life and the relation between the random error of the angular velocity measurement and the surface relief features of the cavity mirrors are analysed. The results of modelling one of the promising approaches to processing the laser gyroscope signals are presented. (laser gyroscopes)

[Clinical study on the coronary artery interventions guided by the magnetic navigation system].

PubMed

Li, Chun-jian; Wang, Hui; Wang, Lian-sheng; Zhu, Tie-bing; Yang, Zhi-jian; Cao, Ke-jiang

2010-03-01

To investigate the efficacy and safety of the magnetic navigation system used in the real world percutaneous coronary artery intervention. All lesions detected by the coronary artery angiography in the magnetic-navigation catheter lab indicated for percutaneous coronary artery intervention (PCI) were included and treated under the guidance of the magnetic navigation system. The characteristics of the target lesion, process of the procedure, time and dosage of the X-ray exposure, and procedure-related complication were recorded and analyzed. One hundred and twenty one patients with 138 lesions were recruited and intervened by PCI during the period from April 2006 to June 2008. Thirty lesions were classified as type A, 50 as type B1, 36 as type B2, 22 as type C (including seven total occlusions). The average stenosis of the target lesions was (85.3 +/- 10.0)%, mean length was (21.1 +/- 10.0) mm. Under the guidance of the magnetic navigation system, 134 target lesions were passed by the magnetic guide-wires, the lesion passing ratio was 97.1%. The X-ray exposure time, X-ray dosage and the contrast volume used during the period of the wire placement were (55.9 +/- 35.4) seconds, (98.0 +/- 86.1) mGy/(490.0 +/- 422.2) microGym(2) and (8.0 +/- 5.4) ml, respectively. A total of 164 stents were implanted in the vessels where the target lesions were passed by the magnetic wires. There was no magnetic navigation system associated complication. Magnetic guide-wires failed to pass four target lesions, two of which were chronic total occlusions (CTOs), and the other two were calcified subtotal occlusions. It is feasible and safe to adopt the magnetic navigation system for the real-world coronary artery intervention. The magnetic guide-wire possesses a high lesion-passing ratio. The CTOs and calcified subtotal occlusions are not ideal lesions for use of the magnetic navigation system.

Method and System for Gamma-Ray Localization Induced Spacecraft Navigation Using Celestial Gamma-Ray Sources

NASA Technical Reports Server (NTRS)

Hisamoto, Chuck (Inventor); Arzoumanian, Zaven (Inventor); Sheikh, Suneel I. (Inventor)

2015-01-01

A method and system for spacecraft navigation using distant celestial gamma-ray bursts which offer detectable, bright, high-energy events that provide well-defined characteristics conducive to accurate time-alignment among spatially separated spacecraft. Utilizing assemblages of photons from distant gamma-ray bursts, relative range between two spacecraft can be accurately computed along the direction to each burst's source based upon the difference in arrival time of the burst emission at each spacecraft's location. Correlation methods used to time-align the high-energy burst profiles are provided. The spacecraft navigation may be carried out autonomously or in a central control mode of operation.

A SINS/SRS/GNS Autonomous Integrated Navigation System Based on Spectral Redshift Velocity Measurements.

PubMed

Wei, Wenhui; Gao, Zhaohui; Gao, Shesheng; Jia, Ke

2018-04-09

In order to meet the requirements of autonomy and reliability for the navigation system, combined with the method of measuring speed by using the spectral redshift information of the natural celestial bodies, a new scheme, consisting of Strapdown Inertial Navigation System (SINS)/Spectral Redshift (SRS)/Geomagnetic Navigation System (GNS), is designed for autonomous integrated navigation systems. The principle of this SINS/SRS/GNS autonomous integrated navigation system is explored, and the corresponding mathematical model is established. Furthermore, a robust adaptive central difference particle filtering algorithm is proposed for this autonomous integrated navigation system. The simulation experiments are conducted and the results show that the designed SINS/SRS/GNS autonomous integrated navigation system possesses good autonomy, strong robustness and high reliability, thus providing a new solution for autonomous navigation technology.

Navigation for space shuttle approach and landing using an inertial navigation system augmented by data from a precision ranging system or a microwave scan beam landing guidance system

NASA Technical Reports Server (NTRS)

Mcgee, L. A.; Smith, G. L.; Hegarty, D. M.; Merrick, R. B.; Carson, T. M.; Schmidt, S. F.

1970-01-01

A preliminary study has been made of the navigation performance which might be achieved for the high cross-range space shuttle orbiter during final approach and landing by using an optimally augmented inertial navigation system. Computed navigation accuracies are presented for an on-board inertial navigation system augmented (by means of an optimal filter algorithm) with data from two different ground navigation aids; a precision ranging system and a microwave scanning beam landing guidance system. These results show that augmentation with either type of ground navigation aid is capable of providing a navigation performance at touchdown which should be adequate for the space shuttle. In addition, adequate navigation performance for space shuttle landing is obtainable from the precision ranging system even with a complete dropout of precision range measurements as much as 100 seconds before touchdown.

Observability during planetary approach navigation

NASA Technical Reports Server (NTRS)

Bishop, Robert H.; Burkhart, P. Daniel; Thurman, Sam W.

1993-01-01

The objective of the research is to develop an analytic technique to predict the relative navigation capability of different Earth-based radio navigation measurements. In particular, the problem is to determine the relative ability of geocentric range and Doppler measurements to detect the effects of the target planet gravitational attraction on the spacecraft during the planetary approach and near-encounter mission phases. A complete solution to the two-dimensional problem has been developed. Relatively simple analytic formulas are obtained for range and Doppler measurements which describe the observability content of the measurement data along the approach trajectories. An observability measure is defined which is based on the observability matrix for nonlinear systems. The results show good agreement between the analytic observability analysis and the computational batch processing method.

Pose Measurement Performance of the Argon Relative Navigation Sensor Suite in Simulated Flight Conditions

NASA Technical Reports Server (NTRS)

Galante, Joseph M.; Eepoel, John Van; Strube, Matt; Gill, Nat; Gonzalez, Marcelo; Hyslop, Andrew; Patrick, Bryan

2012-01-01

Argon is a flight-ready sensor suite with two visual cameras, a flash LIDAR, an on- board flight computer, and associated electronics. Argon was designed to provide sensing capabilities for relative navigation during proximity, rendezvous, and docking operations between spacecraft. A rigorous ground test campaign assessed the performance capability of the Argon navigation suite to measure the relative pose of high-fidelity satellite mock-ups during a variety of simulated rendezvous and proximity maneuvers facilitated by robot manipulators in a variety of lighting conditions representative of the orbital environment. A brief description of the Argon suite and test setup are given as well as an analysis of the performance of the system in simulated proximity and rendezvous operations.

Mackay campus of environmental education and digital cultural construction: the application of 3D virtual reality

NASA Astrophysics Data System (ADS)

Chien, Shao-Chi; Chung, Yu-Wei; Lin, Yi-Hsuan; Huang, Jun-Yi; Chang, Jhih-Ting; He, Cai-Ying; Cheng, Yi-Wen

2012-04-01

This study uses 3D virtual reality technology to create the "Mackay campus of the environmental education and digital cultural 3D navigation system" for local historical sites in the Tamsui (Hoba) area, in hopes of providing tourism information and navigation through historical sites using a 3D navigation system. We used Auto CAD, Sketch Up, and SpaceEyes 3D software to construct the virtual reality scenes and create the school's historical sites, such as the House of Reverends, the House of Maidens, the Residence of Mackay, and the Education Hall. We used this technology to complete the environmental education and digital cultural Mackay campus . The platform we established can indeed achieve the desired function of providing tourism information and historical site navigation. The interactive multimedia style and the presentation of the information will allow users to obtain a direct information response. In addition to showing the external appearances of buildings, the navigation platform can also allow users to enter the buildings to view lifelike scenes and textual information related to the historical sites. The historical sites are designed according to their actual size, which gives users a more realistic feel. In terms of the navigation route, the navigation system does not force users along a fixed route, but instead allows users to freely control the route they would like to take to view the historical sites on the platform.

SoS Navigator 2.0: A Context-Based Approach to System-of-Systems Challenges

DTIC Science & Technology

2008-06-01

in a Postindustrial Age. MIT Press, 1984. [ Kolb 1984] Kolb , David A. Experiential Learning : Experience as the Source of Learning and Develop- ment...terms of experiential learning , and the work of Rosen [Rosen 1991] in terms of the relational approach to understanding anticipa- tive systems. Our...Supporting Techniques and Tools 17  3.2  The Learning /Transformation Cycle 19  3.3  Summary of SoS Navigator Processes and Techniques 20  4  Case Summaries 22

Design and validation of a GNC system for missions to asteroids: the AIM scenario

NASA Astrophysics Data System (ADS)

Pellacani, A.; Kicman, P.; Suatoni, M.; Casasco, M.; Gil, J.; Carnelli, I.

2017-12-01

Deep space missions, and in particular missions to asteroids, impose a certain level of autonomy that depends on the mission objectives. If the mission requires the spacecraft to perform close approaches to the target body (the extreme case being a landing scenario), the autonomy level must be increased to guarantee the fast and reactive response which is required in both nominal and contingency operations. The GNC system must be designed in accordance with the required level of autonomy. The GNC system designed and tested in the frame of ESA's Asteroid Impact Mission (AIM) system studies (Phase A/B1 and Consolidation Phase) is an example of an autonomous GNC system that meets the challenging objectives of AIM. The paper reports the design of such GNC system and its validation through a DDVV plan that includes Model-in-the-Loop and Hardware-in-the-Loop testing. Main focus is the translational navigation, which is able to provide online the relative state estimation with respect to the target body using exclusively cameras as relative navigation sensors. The relative navigation outputs are meant to be used for nominal spacecraft trajectory corrections as well as to estimate the collision risk with the asteroid and, if needed, to command the execution of a collision avoidance manoeuvre to guarantee spacecraft safety

Crew aiding and automation: A system concept for terminal area operations, and guidelines for automation design

NASA Technical Reports Server (NTRS)

Dwyer, John P.

1994-01-01

This research and development program comprised two efforts: the development of guidelines for the design of automated systems, with particular emphasis on automation design that takes advantage of contextual information, and the concept-level design of a crew aiding system, the Terminal Area Navigation Decision Aiding Mediator (TANDAM). This concept outlines a system capable of organizing navigation and communication information and assisting the crew in executing the operations required in descent and approach. In service of this endeavor, problem definition activities were conducted that identified terminal area navigation and operational familiarization exercises addressing the terminal area navigation problem. Both airborne and ground-based (ATC) elements of aircraft control were extensively researched. The TANDAM system concept was then specified, and the crew interface and associated systems described. Additionally, three descent and approach scenarios were devised in order to illustrate the principal functions of the TANDAM system concept in relation to the crew, the aircraft, and ATC. A plan for the evaluation of the TANDAM system was established. The guidelines were developed based on reviews of relevant literature, and on experience gained in the design effort.

INL Autonomous Navigation System

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

2005-03-30

The INL Autonomous Navigation System provides instructions for autonomously navigating a robot. The system permits high-speed autonomous navigation including obstacle avoidance, waypoing navigation and path planning in both indoor and outdoor environments.

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

NASA Astrophysics Data System (ADS)

Hwang, Soon Sik

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.

A SINS/SRS/GNS Autonomous Integrated Navigation System Based on Spectral Redshift Velocity Measurements

PubMed Central

Wei, Wenhui; Gao, Zhaohui; Gao, Shesheng; Jia, Ke

2018-01-01

In order to meet the requirements of autonomy and reliability for the navigation system, combined with the method of measuring speed by using the spectral redshift information of the natural celestial bodies, a new scheme, consisting of Strapdown Inertial Navigation System (SINS)/Spectral Redshift (SRS)/Geomagnetic Navigation System (GNS), is designed for autonomous integrated navigation systems. The principle of this SINS/SRS/GNS autonomous integrated navigation system is explored, and the corresponding mathematical model is established. Furthermore, a robust adaptive central difference particle filtering algorithm is proposed for this autonomous integrated navigation system. The simulation experiments are conducted and the results show that the designed SINS/SRS/GNS autonomous integrated navigation system possesses good autonomy, strong robustness and high reliability, thus providing a new solution for autonomous navigation technology. PMID:29642549

Autonomous vision-based navigation for proximity operations around binary asteroids

NASA Astrophysics Data System (ADS)

Gil-Fernandez, Jesus; Ortega-Hernando, Guillermo

2018-02-01

Future missions to small bodies demand higher level of autonomy in the Guidance, Navigation and Control system for higher scientific return and lower operational costs. Different navigation strategies have been assessed for ESA's asteroid impact mission (AIM). The main objective of AIM is the detailed characterization of binary asteroid Didymos. The trajectories for the proximity operations shall be intrinsically safe, i.e., no collision in presence of failures (e.g., spacecraft entering safe mode), perturbations (e.g., non-spherical gravity field), and errors (e.g., maneuver execution error). Hyperbolic arcs with sufficient hyperbolic excess velocity are designed to fulfil the safety, scientific, and operational requirements. The trajectory relative to the asteroid is determined using visual camera images. The ground-based trajectory prediction error at some points is comparable to the camera Field Of View (FOV). Therefore, some images do not contain the entire asteroid. Autonomous navigation can update the state of the spacecraft relative to the asteroid at higher frequency. The objective of the autonomous navigation is to improve the on-board knowledge compared to the ground prediction. The algorithms shall fit in off-the-shelf, space-qualified avionics. This note presents suitable image processing and relative-state filter algorithms for autonomous navigation in proximity operations around binary asteroids.

Autonomous vision-based navigation for proximity operations around binary asteroids

NASA Astrophysics Data System (ADS)

Gil-Fernandez, Jesus; Ortega-Hernando, Guillermo

2018-06-01

Future missions to small bodies demand higher level of autonomy in the Guidance, Navigation and Control system for higher scientific return and lower operational costs. Different navigation strategies have been assessed for ESA's asteroid impact mission (AIM). The main objective of AIM is the detailed characterization of binary asteroid Didymos. The trajectories for the proximity operations shall be intrinsically safe, i.e., no collision in presence of failures (e.g., spacecraft entering safe mode), perturbations (e.g., non-spherical gravity field), and errors (e.g., maneuver execution error). Hyperbolic arcs with sufficient hyperbolic excess velocity are designed to fulfil the safety, scientific, and operational requirements. The trajectory relative to the asteroid is determined using visual camera images. The ground-based trajectory prediction error at some points is comparable to the camera Field Of View (FOV). Therefore, some images do not contain the entire asteroid. Autonomous navigation can update the state of the spacecraft relative to the asteroid at higher frequency. The objective of the autonomous navigation is to improve the on-board knowledge compared to the ground prediction. The algorithms shall fit in off-the-shelf, space-qualified avionics. This note presents suitable image processing and relative-state filter algorithms for autonomous navigation in proximity operations around binary asteroids.

Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles.

PubMed

Atman, Jamal; Popp, Manuel; Ruppelt, Jan; Trommer, Gert F

2016-09-16

Micro Air Vehicles (MAVs) equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS). In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV's navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P) problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results.

Cobalt: Development and Maturation of GN&C Technologies for Precision Landing

NASA Technical Reports Server (NTRS)

Carson, John M.; Restrepo, Carolina; Seubert, Carl; Amzajerdian, Farzin

2016-01-01

The CoOperative Blending of Autonomous Landing Technologies (COBALT) instrument is a terrestrial test platform for development and maturation of guidance, navigation and control (GN&C) technologies for precision landing. The project is developing a third-generation Langley Research Center (LaRC) navigation doppler lidar (NDL) for ultra-precise velocity and range measurements, which will be integrated and tested with the Jet Propulsion Laboratory (JPL) lander vision system (LVS) for terrain relative navigation (TRN) position estimates. These technologies together provide precise navigation knowledge that is critical for a controlled and precise touchdown. The COBALT hardware will be integrated in 2017 into the GN&C subsystem of the Xodiac rocket-propulsive vertical test bed (VTB) developed by Masten Space Systems, and two terrestrial flight campaigns will be conducted: one open-loop (i.e., passive) and one closed-loop (i.e., active).

A Novel Augmented Reality Navigation System for Endoscopic Sinus and Skull Base Surgery: A Feasibility Study

PubMed Central

Li, Liang; Yang, Jian; Chu, Yakui; Wu, Wenbo; Xue, Jin; Liang, Ping; Chen, Lei

2016-01-01

Objective To verify the reliability and clinical feasibility of a self-developed navigation system based on an augmented reality technique for endoscopic sinus and skull base surgery. Materials and Methods In this study we performed a head phantom and cadaver experiment to determine the display effect and accuracy of our navigational system. We compared cadaver head-based simulated operations, the target registration error, operation time, and National Aeronautics and Space Administration Task Load Index scores of our navigation system to conventional navigation systems. Results The navigation system developed in this study has a novel display mode capable of fusing endoscopic images to three-dimensional (3-D) virtual images. In the cadaver head experiment, the target registration error was 1.28 ± 0.45 mm, which met the accepted standards of a navigation system used for nasal endoscopic surgery. Compared with conventional navigation systems, the new system was more effective in terms of operation time and the mental workload of surgeons, which is especially important for less experienced surgeons. Conclusion The self-developed augmented reality navigation system for endoscopic sinus and skull base surgery appears to have advantages that outweigh those of conventional navigation systems. We conclude that this navigational system will provide rhinologists with more intuitive and more detailed imaging information, thus reducing the judgment time and mental workload of surgeons when performing complex sinus and skull base surgeries. Ultimately, this new navigational system has potential to increase the quality of surgeries. In addition, the augmented reality navigational system could be of interest to junior doctors being trained in endoscopic techniques because it could speed up their learning. However, it should be noted that the navigation system serves as an adjunct to a surgeon’s skills and knowledge, not as a substitute. PMID:26757365

A Novel Augmented Reality Navigation System for Endoscopic Sinus and Skull Base Surgery: A Feasibility Study.

PubMed

Li, Liang; Yang, Jian; Chu, Yakui; Wu, Wenbo; Xue, Jin; Liang, Ping; Chen, Lei

2016-01-01

To verify the reliability and clinical feasibility of a self-developed navigation system based on an augmented reality technique for endoscopic sinus and skull base surgery. In this study we performed a head phantom and cadaver experiment to determine the display effect and accuracy of our navigational system. We compared cadaver head-based simulated operations, the target registration error, operation time, and National Aeronautics and Space Administration Task Load Index scores of our navigation system to conventional navigation systems. The navigation system developed in this study has a novel display mode capable of fusing endoscopic images to three-dimensional (3-D) virtual images. In the cadaver head experiment, the target registration error was 1.28 ± 0.45 mm, which met the accepted standards of a navigation system used for nasal endoscopic surgery. Compared with conventional navigation systems, the new system was more effective in terms of operation time and the mental workload of surgeons, which is especially important for less experienced surgeons. The self-developed augmented reality navigation system for endoscopic sinus and skull base surgery appears to have advantages that outweigh those of conventional navigation systems. We conclude that this navigational system will provide rhinologists with more intuitive and more detailed imaging information, thus reducing the judgment time and mental workload of surgeons when performing complex sinus and skull base surgeries. Ultimately, this new navigational system has potential to increase the quality of surgeries. In addition, the augmented reality navigational system could be of interest to junior doctors being trained in endoscopic techniques because it could speed up their learning. However, it should be noted that the navigation system serves as an adjunct to a surgeon's skills and knowledge, not as a substitute.

Light Detection and Ranging-Based Terrain Navigation: A Concept Exploration

NASA Technical Reports Server (NTRS)

Campbell, Jacob; UijtdeHaag, Maarten; vanGraas, Frank; Young, Steve

2003-01-01

This paper discusses the use of Airborne Light Detection And Ranging (LiDAR) equipment for terrain navigation. Airborne LiDAR is a relatively new technology used primarily by the geo-spatial mapping community to produce highly accurate and dense terrain elevation maps. In this paper, the term LiDAR refers to a scanning laser ranger rigidly mounted to an aircraft, as opposed to an integrated sensor system that consists of a scanning laser ranger integrated with Global Positioning System (GPS) and Inertial Measurement Unit (IMU) data. Data from the laser range scanner and IMU will be integrated with a terrain database to estimate the aircraft position and data from the laser range scanner will be integrated with GPS to estimate the aircraft attitude. LiDAR data was collected using NASA Dryden's DC-8 flying laboratory in Reno, NV and was used to test the proposed terrain navigation system. The results of LiDAR-based terrain navigation shown in this paper indicate that airborne LiDAR is a viable technology enabler for fully autonomous aircraft navigation. The navigation performance is highly dependent on the quality of the terrain databases used for positioning and therefore high-resolution (2 m post-spacing) data was used as the terrain reference.

ULTOR(Registered TradeMark) Passive Pose and Position Engine For Spacecraft Relative Navigation

NASA Technical Reports Server (NTRS)

Hannah, S. Joel

2008-01-01

The ULTOR(Registered TradeMark) Passive Pose and Position Engine (P3E) technology, developed by Advanced Optical Systems, Inc (AOS), uses real-time image correlation to provide relative position and pose data for spacecraft guidance, navigation, and control. Potential data sources include a wide variety of sensors, including visible and infrared cameras. ULTOR(Registered TradeMark) P3E has been demonstrated on a number of host processing platforms. NASA is integrating ULTOR(Registerd TradeMark) P3E into its Relative Navigation System (RNS), which is being developed for the upcoming Hubble Space Telescope (HST) Servicing Mission 4 (SM4). During SM4 ULTOR(Registered TradeMark) P3E will perform realtime pose and position measurements during both the approach and departure phases of the mission. This paper describes the RNS implementation of ULTOR(Registered TradeMark) P3E, and presents results from NASA's hardware-in-the-loop simulation testing against the HST mockup.

An Environmental for Hardware-in-the-Loop Formation Navigation and Control

NASA Technical Reports Server (NTRS)

Burns, Rich; Naasz, Bo; Gaylor, Dave; Higinbotham, John

2004-01-01

Recent interest in formation flying satellite systems has spurred a considerable amount of research in the relative navigation and control of satellites. Development in this area has included new estimation and control algorithms as well as sensor and actuator development specifically geared toward the relative control problem. This paper describes a simulation facility, the Formation Flying Test Bed (FFTB) at NASA Goddard Space Flight Center, which allows engineers to test new algorithms for the formation flying problem with relevant GN&C hardware in a closed loop simulation. The FFTB currently supports the inclusion of GPS receiver hardware in the simulation loop. Support for satellite crosslink ranging technology is at a prototype stage. This closed-loop, hardware inclusive simulation capability permits testing of navigation and control software in the presence of the actual hardware with which the algorithms must interact. This capability provides the navigation or control developer with a perspective on how the algorithms perform as part of the closed-loop system. In this paper, the overall design and evolution of the FFTB are presented. Each component of the FFTB is then described. Interfaces between the components of the FFTB are shown and the interfaces to and between navigation and control software are described. Finally, an example of closed-loop formation control with GPS receivers in the loop is presented.

Real-Time Hazard Detection and Avoidance Demonstration for a Planetary Lander

NASA Technical Reports Server (NTRS)

Epp, Chirold D.; Robertson, Edward A.; Carson, John M., III

2014-01-01

The Autonomous Landing Hazard Avoidance Technology (ALHAT) Project is chartered to develop and mature to a Technology Readiness Level (TRL) of six an autonomous system combining guidance, navigation and control with terrain sensing and recognition functions for crewed, cargo, and robotic planetary landing vehicles. In addition to precision landing close to a pre-mission defined landing location, the ALHAT System must be capable of autonomously identifying and avoiding surface hazards in real-time to enable a safe landing under any lighting conditions. This paper provides an overview of the recent results of the ALHAT closed loop hazard detection and avoidance flight demonstrations on the Morpheus Vertical Testbed (VTB) at the Kennedy Space Center, including results and lessons learned. This effort is also described in the context of a technology path in support of future crewed and robotic planetary exploration missions based upon the core sensing functions of the ALHAT system: Terrain Relative Navigation (TRN), Hazard Detection and Avoidance (HDA), and Hazard Relative Navigation (HRN).

Apollo Onboard Navigation Techniques

NASA Technical Reports Server (NTRS)

Interbartolo, Michael

2009-01-01

This viewgraph presentation reviews basic navigation concepts, describes coordinate systems and identifies attitude determination techniques including Primary Guidance, Navigation and Control System (PGNCS) IMU management and Command and Service Module Stabilization and Control System/Lunar Module (LM) Abort Guidance System (AGS) attitude management. The presentation also identifies state vector determination techniques, including PGNCS coasting flight navigation, PGNCS powered flight navigation and LM AGS navigation.

33 CFR 62.1 - Purpose.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.1 Purpose. (a) The Coast Guard administers the U.S. Aids to Navigation System. The system consists of Federal aids to navigation operated by the Coast Guard, aids to...

33 CFR 62.1 - Purpose.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.1 Purpose. (a) The Coast Guard administers the U.S. Aids to Navigation System. The system consists of Federal aids to navigation operated by the Coast Guard, aids to...

33 CFR 62.1 - Purpose.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.1 Purpose. (a) The Coast Guard administers the U.S. Aids to Navigation System. The system consists of Federal aids to navigation operated by the Coast Guard, aids to...

33 CFR 62.1 - Purpose.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.1 Purpose. (a) The Coast Guard administers the U.S. Aids to Navigation System. The system consists of Federal aids to navigation operated by the Coast Guard, aids to...

33 CFR 62.1 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.1 Purpose. (a) The Coast Guard administers the U.S. Aids to Navigation System. The system consists of Federal aids to navigation operated by the Coast Guard, aids to...

A real-time algorithm for integrating differential satellite and inertial navigation information during helicopter approach. M.S. Thesis

NASA Technical Reports Server (NTRS)

Hoang, TY

1994-01-01

A real-time, high-rate precision navigation Kalman filter algorithm is developed and analyzed. This Navigation algorithm blends various navigation data collected during terminal area approach of an instrumented helicopter. Navigation data collected include helicopter position and velocity from a global position system in differential mode (DGPS) as well as helicopter velocity and attitude from an inertial navigation system (INS). The goal of the Navigation algorithm is to increase the DGPS accuracy while producing navigational data at the 64 Hertz INS update rate. It is important to note that while the data was post flight processed, the Navigation algorithm was designed for real-time analysis. The design of the Navigation algorithm resulted in a nine-state Kalman filter. The Kalman filter's state matrix contains position, velocity, and velocity bias components. The filter updates positional readings with DGPS position, INS velocity, and velocity bias information. In addition, the filter incorporates a sporadic data rejection scheme. This relatively simple model met and exceeded the ten meter absolute positional requirement. The Navigation algorithm results were compared with truth data derived from a laser tracker. The helicopter flight profile included terminal glideslope angles of 3, 6, and 9 degrees. Two flight segments extracted during each terminal approach were used to evaluate the Navigation algorithm. The first segment recorded small dynamic maneuver in the lateral plane while motion in the vertical plane was recorded by the second segment. The longitudinal, lateral, and vertical averaged positional accuracies for all three glideslope approaches are as follows (mean plus or minus two standard deviations in meters): longitudinal (-0.03 plus or minus 1.41), lateral (-1.29 plus or minus 2.36), and vertical (-0.76 plus or minus 2.05).

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

NASA Astrophysics Data System (ADS)

Moafipoor, Shahram

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 this dissertation, the underlying assumption is that the system does not require pre-existing infrastructure to enable pedestrian navigation. To facilitate this capability, a multisensor system concept, based on the Global Positioning System (GPS), inertial navigation, barometer, magnetometer, and a human pedometry model has been developed. An important aspect of this design is to use the human body as navigation sensor to facilitate Dead Reckoning (DR) navigation in GPS-challenged environments. The system is designed predominantly for outdoor environments, where occasional loss of GPS lock may happen; however, testing and performance demonstration have been extended to indoor environments. DR navigation is based on a relative-measurement approach, with the key idea of integrating the incremental motion information in the form of step direction (SD) and step length (SL) over time. The foundation of the intelligent navigation system concept proposed here rests in exploiting the human locomotion pattern, as well as change of locomotion in varying environments. In this context, the term intelligent navigation represents the transition from the conventional point-to-point DR to dynamic navigation using the knowledge about the mechanism of the moving person. This approach increasingly relies on integrating knowledge-based systems (KBS) and artificial intelligence (AI) methodologies, including artificial neural networks (ANN) and fuzzy logic (FL). In addition, a general framework of the quality control for the real-time validation of the DR processing is proposed, based on a two-stage Kalman Filter approach. The performance comparison of the algorithm based on different field and simulated datasets, with varying levels of sensor errors, showed that 90 per cent success rate was achieved in detection of outliers for SL and 80 per cent for SD. The SL is predicted for both KBS-based ANN and FL approaches with an average accumulated error of 2 per cent, observed for the total distance traveled, which is generally an improvement over most of the existing pedometry systems. The target accuracy of the system is +/-(3-5)m CEP50 (circular error, probable 50%). This dissertation provides a performance analysis in the outdoor and indoor environments for different operators. Another objective of this dissertation is to test the system's navigation limitation in DR mode in terms of time and trajectory length in order to determine the upper limit of indoor operations. It was determined that for more than four indoor loops, where the user walked 261m in about 6.5 minutes, the DR performance met the required accuracy specifications. However, these results are only relevant to the existing data. Future studies should consider more comprehensive performance analysis for longer trajectories in challenging environments and possible extension to image-based navigation to expand the indoor capability of the system.

3D point cloud analysis of structured light registration in computer-assisted navigation in spinal surgeries

NASA Astrophysics Data System (ADS)

Gupta, Shaurya; Guha, Daipayan; Jakubovic, Raphael; Yang, Victor X. D.

2017-02-01

Computer-assisted navigation is used by surgeons in spine procedures to guide pedicle screws to improve placement accuracy and in some cases, to better visualize patient's underlying anatomy. Intraoperative registration is performed to establish a correlation between patient's anatomy and the pre/intra-operative image. Current algorithms rely on seeding points obtained directly from the exposed spinal surface to achieve clinically acceptable registration accuracy. Registration of these three dimensional surface point-clouds are prone to various systematic errors. The goal of this study was to evaluate the robustness of surgical navigation systems by looking at the relationship between the optical density of an acquired 3D point-cloud and the corresponding surgical navigation error. A retrospective review of a total of 48 registrations performed using an experimental structured light navigation system developed within our lab was conducted. For each registration, the number of points in the acquired point cloud was evaluated relative to whether the registration was acceptable, the corresponding system reported error and target registration error. It was demonstrated that the number of points in the point cloud neither correlates with the acceptance/rejection of a registration or the system reported error. However, a negative correlation was observed between the number of the points in the point-cloud and the corresponding sagittal angular error. Thus, system reported total registration points and accuracy are insufficient to gauge the accuracy of a navigation system and the operating surgeon must verify and validate registration based on anatomical landmarks prior to commencing surgery.

Reduction effect of the quantity of radiation exposure and contrast media by image support system in transarterial chemoembolization for the treatment of hepatocellular carcinoma.

PubMed

Tamai, Tsutomu; Taniyama, Oki; Oda, Kohei; Kasai, Ai; Ijyuin, Syo; Sakae, Haruka; Onishi, Hiroka; Tabu, Kazuaki; Kumagai, Kotaro; Mawatari, Seiichi; Moriuchi, Akihiro; Uto, Hirofumi; Ido, Akio

2018-05-01

We confirmed the clinical utility of a three-dimensional navigation system during transarterial chemoembolization. We evaluated 128 tumors in 91 patients enrolled between May 2015 and August 2016. We evaluated the accuracy of the three-dimensional navigation imaging system for all tumors. We compared the patients who were able to undergo route detection using three-dimensional navigation with previously treated patients who underwent transarterial chemoembolization without using three-dimensional navigation (n = 21). For 38 patients who underwent super-selective microcatheter insertion after a feeding artery was identified by three-dimensional navigation, we confirmed the relationship between the tumors and contrasted liver parenchyma and divided the computed tomography hepatic arteriography findings into four grades. Grade 1: an overlap of > 5 mm, grade 2: an overlap between 0 and 5 mm, grade 3: the borders of the tumor within the liver parenchyma but in contact with the edges, and grade 4: a tumor outside the borders of the liver parenchyma. Using the three-dimensional navigation system, we identified a tumor-feeding artery in 125/128 tumors (97.6%). Furthermore, this system allowed us to significantly reduce the volume of contrast media and the radiation exposure dose in patients undergoing an evaluation. We identified 15 grade 1 tumors (39.5%), 3 grade 2 tumors (7.9%), 11 grade 3 tumors (28.9%), and 9 grade 4 tumors (23.7%) according to our definitions. The three-dimensional navigation is useful not only for patients but also for surgeons who have relatively little experience. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Relative Navigation Algorithms for Phase 1 of the MMS Formation

NASA Technical Reports Server (NTRS)

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

2003-01-01

This paper evaluates several navigation approaches for the first phase of the Magnetospheric Multiscale (MMS) mission, which consists of a tetrahedral formation of four satellites in highly eccentric Earth orbits of approximately 1.2 by 12 Earth radii at an inclination of 10 degrees. The inter-satellite separation is approximately 10 kilometers near apogees. Navigation approaches were studied using ground station m g e =d two-way Doppler measurements, Global Positioning System (GPS) pseudorange measurements, crosslink range measurements among the members flying in formation, and various combinations of these measurement types. An absolute position accuracy of 10 kilometers or better can be achieved with most of the approaches studied and a relative position accuracy of 100 meters or better can be achieved at apogee in some cases. Among the various approaches studied, the approaches that use a combination of GPS and crosslink measurements were found to be more reliable in terms of absolute and relative navigation accuracies and operational flexibility.

A dataset on human navigation strategies in foreign networked systems.

PubMed

Kőrösi, Attila; Csoma, Attila; Rétvári, Gábor; Heszberger, Zalán; Bíró, József; Tapolcai, János; Pelle, István; Klajbár, Dávid; Novák, Márton; Halasi, Valentina; Gulyás, András

2018-03-13

Humans are involved in various real-life networked systems. The most obvious examples are social and collaboration networks but the language and the related mental lexicon they use, or the physical map of their territory can also be interpreted as networks. How do they find paths between endpoints in these networks? How do they obtain information about a foreign networked world they find themselves in, how they build mental model for it and how well they succeed in using it? Large, open datasets allowing the exploration of such questions are hard to find. Here we report a dataset collected by a smartphone application, in which players navigate between fixed length source and destination English words step-by-step by changing only one letter at a time. The paths reflect how the players master their navigation skills in such a foreign networked world. The dataset can be used in the study of human mental models for the world around us, or in a broader scope to investigate the navigation strategies in complex networked systems.

[Magnetic navigation for ablation of cardiac arrhythmias].

PubMed

Chen, Jian; Hoff, Per Ivar; Solheim, Eivind; Schuster, Peter; Off, Morten Kristian; Ohm, Ole-Jørgen

2010-08-12

The first use of magnetic navigation for radiofrequency ablation of supraventricular tachycardias, was published in 2004. Subsequently, the method has been used for treatment of most types of tachyarrhythmias. This paper provides an overview of the method, with special emphasis on usefulness of a new remote-controlled magnetic navigation system. The paper is based on our own scientific experience and literature identified through a non-systematic search in PubMed. The magnetic navigation system consists of two external electromagnets (to be placed on opposite sides of the patient), which guide an ablation catheter (with a small magnet at the tip of the catheter) to the target area in the heart. The accuracy of this procedure is higher than that with manual navigation. Personnel can be quickly trained to use remote magnetic navigation, but the procedure itself is time-consuming, particularly for patients with atrial fibrillation. The major advantage is a considerably lower radiation burden to both patient and operator, in some studies more than 50 %, and a corresponding reduction in physical strain on the operator. The incidence of procedure-related complications seems to be lower than that observed with use of manually operated ablation catheters. Work is ongoing to improve magnetic ablation catheters and methods that can simplify mapping procedures and improve efficacy of arrhythmia ablation. The basic cost for installing a complete magnetic navigation laboratory may be three times that of a conventional electrophysiological laboratory. The new magnetic navigation system has proved to be applicable during ablation for a variety of tachyarrhythmias, but is still under development.

Relative Navigation Strategies for the Magnetopheric Multiscale Mission

NASA Technical Reports Server (NTRS)

Gramling, Cheryl; Carpenter, Russell; Lee, Taesul; Long, Anne

2004-01-01

This paper evaluates several navigation approaches for the Magnetospheric Multiscale (MMS) mission, which consists of a tetrahedral formation of satellites flying in highly eccentric Earth orbits. For this investigation, inter-satellite separations of approximately 10 kilometers near apogee are used for the first two phases of the MMS mission. Navigation approaches were studied using ground station two-way Doppler measurements, Global Positioning System (GPS) pseudorange measurements, and cross-link range measurements between the members of the formation. An absolute position accuracy of 15 kilometers or better can be achieved with most of the approaches studied, and a relative position accuracy of 100 meters or better can be achieved at apogee in several cases.

Oncology navigators' perceptions of cancer-related financial burden and financial assistance resources.

PubMed

Spencer, Jennifer C; Samuel, Cleo A; Rosenstein, Donald L; Reeder-Hayes, Katherine E; Manning, Michelle L; Sellers, Jean B; Wheeler, Stephanie B

2018-04-01

As the cost of cancer treatment continues to rise, many patients are faced with significant emotional and financial burden. Oncology navigators guide patients through many aspects of care and therefore may be especially aware of patients' financial distress. Our objective was to explore navigators' perception of their patients' financial burden and their role in addressing financial needs. We conducted a real-time online survey of attendees at an oncology navigators' association conference. Participants included lay navigators, oncology nurse navigators, community health workers, and social workers. Questions assessed perceived burden in their patient population and their role in helping navigate patients through financial resources. Answers to open-ended questions are reported using identified themes. Seventy-eight respondents participated in the survey, reporting that on average 75% of their patients experienced some degree of financial toxicity related to their cancer. Only 45% of navigators felt the majority of these patients were able to get some financial assistance, most often through assistance with medical costs (73%), subsidized insurance (36%), or non-medical expenses (31%). Commonly identified barriers for patients obtaining assistance included lack of resources (50%), lack of knowledge about resources (46%), and complex/duplicative paperwork (20%). Oncology navigators reported a high burden of financial toxicity among their patients but insufficient knowledge or resources to address this need. This study underscores the importance of improved training and coordination for addressing financial burden, and the need to address community and system-level barriers.

Relative navigation for spacecraft formation flying

NASA Technical Reports Server (NTRS)

Hartman, Kate R.; Gramling, Cheryl J.; Lee, Taesul; Kelbel, David A.; Long, Anne C.

1998-01-01

The Goddard Space Flight Center Guidance, Navigation, and Control Center (GNCC) is currently developing and implementing advanced satellite systems to provide autonomous control of formation flyers. The initial formation maintenance capability will be flight-demonstrated on the Earth-Orbiter-1 (EO-1) satellite, which is planned under the National Aeronautics and Space Administration New Millennium Program to be a coflight with the Landsat-7 (L-7) satellite. Formation flying imposes relative navigation accuracy requirements in addition to the orbit accuracy requirements for the individual satellites. In the case of EO-1 and L-7, the two satellites are in nearly coplanar orbits, with a small difference in the longitude of the ascending node to compensate for the Earth's rotation. The GNCC has performed trajectory error analysis for the relative navigation of the EO-1/L-7 formation, as well as for a more advanced tracking configuration using cross-link satellite communications. This paper discusses the orbit determination and prediction accuracy achievable for EO-1 and L-7 under various tracking and orbit determination scenarios and discusses the expected relative separation errors in their formation flying configuration.

Relative Navigation for Spacecraft Formation Flying

NASA Technical Reports Server (NTRS)

Hartman, Kate R.; Gramling, Cheryl J.; Lee, Taesul; Kelbel, David A.; Long, Anne C.

1998-01-01

The Goddard Space Flight Center Guidance, Navigation, and Control Center (GNCC) is currently developing and implementing advanced satellite systems to provide autonomous control of formation flyers. The initial formation maintenance capability will be flight-demonstrated on the Earth-Orbiter-1 (EO-l) satellite, which is planned under the National Aeronautics and Space Administration New Millennium Program to be a coflight with the Landsat-7 (L-7) satellite. Formation flying imposes relative navigation accuracy requirements in addition to the orbit accuracy requirements for the individual satellites. In the case of EO-1 and L-7, the two satellites are in nearly coplanar orbits, with a small difference in the longitude of the ascending node to compensate for the Earth's rotation. The GNCC has performed trajectory error analysis for the relative navigation of the EO-1/L-7 formation, as well as for a more advanced tracking configuration using cross- link satellite communications. This paper discusses the orbit determination and prediction accuracy achievable for EO-1 and L-7 under various tracking and orbit determination scenarios and discusses the expected relative separation errors in their formation flying configuration.

Ground Simulation of an Autonomous Satellite Rendezvous and Tracking System Using Dual Robotic Systems

NASA Technical Reports Server (NTRS)

Trube, Matthew J.; Hyslop, Andrew M.; Carignan, Craig R.; Easley, Joseph W.

2012-01-01

A hardware-in-the-loop ground system was developed for simulating a robotic servicer spacecraft tracking a target satellite at short range. A relative navigation sensor package "Argon" is mounted on the end-effector of a Fanuc 430 manipulator, which functions as the base platform of the robotic spacecraft servicer. Machine vision algorithms estimate the pose of the target spacecraft, mounted on a Rotopod R-2000 platform, relay the solution to a simulation of the servicer spacecraft running in "Freespace", which performs guidance, navigation and control functions, integrates dynamics, and issues motion commands to a Fanuc platform controller so that it tracks the simulated servicer spacecraft. Results will be reviewed for several satellite motion scenarios at different ranges. Key words: robotics, satellite, servicing, guidance, navigation, tracking, control, docking.

A navigation system for the visually impaired using colored navigation lines and RFID tags.

PubMed

Seto, First Tatsuya

2009-01-01

In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. Our developed instrument consists of a navigation system and a map information system. These systems are installed on a white cane. Our navigation system can follow a colored navigation line that is set on the floor. In this system, a color sensor installed on the tip of a white cane senses the colored navigation line, and the system informs the visually impaired that he/she is walking along the navigation line by vibration. The color recognition system is controlled by a one-chip microprocessor and this system can discriminate 6 colored navigation lines. RFID tags and a receiver for these tags are used in the map information system. The RFID tags and the RFID tag receiver are also installed on a white cane. The receiver receives tag information and notifies map information to the user by mp3 formatted pre-recorded voice. Three normal subjects who were blindfolded with an eye mask were tested with this system. All of them were able to walk along the navigation line. The performance of the map information system was good. Therefore, our system will be extremely valuable in supporting the activities of the visually impaired.

Analysis of DGPS/INS and MLS/INS final approach navigation errors and control performance data

NASA Technical Reports Server (NTRS)

Hueschen, Richard M.; Spitzer, Cary R.

1992-01-01

Flight tests were conducted jointly by NASA Langley Research Center and Honeywell, Inc., on a B-737 research aircraft to record a data base for evaluating the performance of a differential DGPS/inertial navigation system (INS) which used GPS Course/Acquisition code receivers. Estimates from the DGPS/INS and a Microwave Landing System (MLS)/INS, and various aircraft parameter data were recorded in real time aboard the aircraft while flying along the final approach path to landing. This paper presents the mean and standard deviation of the DGPS/INS and MLS/INS navigation position errors computed relative to the laser tracker system and of the difference between the DGPS/INS and MLS/INS velocity estimates. RMS errors are presented for DGPS/INS and MLS/INS guidance errors (localizer and glideslope). The mean navigation position errors and standard deviation of the x position coordinate of the DGPS/INS and MLS/INS systems were found to be of similar magnitude while the standard deviation of the y and z position coordinate errors were significantly larger for DGPS/INS compared to MLS/INS.

33 CFR 62.63 - Recommendations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Recommendations. 62.63 Section 62.63 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63...

The Mathematics of Navigating the Solar System

NASA Technical Reports Server (NTRS)

Hintz, Gerald

2000-01-01

In navigating spacecraft throughout the solar system, the space navigator relies on three academic disciplines - optimization, estimation, and control - that work on mathematical models of the real world. Thus, the navigator determines the flight path that will consume propellant and other resources in an efficient manner, determines where the craft is and predicts where it will go, and transfers it onto the optimal trajectory that meets operational and mission constraints. Mission requirements, for example, demand that observational measurements be made with sufficient precision that relativity must be modeled in collecting and fitting (the estimation process) the data, and propagating the trajectory. Thousands of parameters are now determined in near real-time to model the gravitational forces acting on a spacecraft in the vicinity of an irregularly shaped body. Completing these tasks requires mathematical models, analyses, and processing techniques. Newton, Gauss, Lambert, Legendre, and others are justly famous for their contributions to the mathematics of these tasks. More recently, graduate students participated in research to update the gravity model of the Saturnian system, including higher order gravity harmonics, tidal effects, and the influence of the rings. This investigation was conducted for the Cassini project to incorporate new trajectory modeling features in the navigation software. The resulting trajectory model will be used in navigating the 4-year tour of the Saturnian satellites. Also, undergraduate students are determining the ephemerides (locations versus time) of asteroids that will be used as reference objects in navigating the New Millennium's Deep Space 1 spacecraft autonomously.

Vision-Based 3D Motion Estimation for On-Orbit Proximity Satellite Tracking and Navigation

DTIC Science & Technology

2015-06-01

Multiple-Purpose Crew Vehicle (MPVC), which will be provided with a LIDAR sensor as primary relative navigation system [26, 33, 34]. A drawback of LIDAR...328–352, 2009. [63] C. Luigini and M. Romano, “A ballistic- pendulum test stand to characterize small cold-gas thruster nozzles,” Acta

Flight Testing ALHAT Precision Landing Technologies Integrated Onboard the Morpheus Rocket Vehicle

NASA Technical Reports Server (NTRS)

Carson, John M. III; Robertson, Edward A.; Trawny, Nikolas; Amzajerdian, Farzin

2015-01-01

A suite of prototype sensors, software, and avionics developed within the NASA Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project were terrestrially demonstrated onboard the NASA Morpheus rocket-propelled Vertical Testbed (VTB) in 2014. The sensors included a LIDAR-based Hazard Detection System (HDS), a Navigation Doppler LIDAR (NDL) velocimeter, and a long-range Laser Altimeter (LAlt) that enable autonomous and safe precision landing of robotic or human vehicles on solid solar system bodies under varying terrain lighting conditions. The flight test campaign with the Morpheus vehicle involved a detailed integration and functional verification process, followed by tether testing and six successful free flights, including one night flight. The ALHAT sensor measurements were integrated into a common navigation solution through a specialized ALHAT Navigation filter that was employed in closed-loop flight testing within the Morpheus Guidance, Navigation and Control (GN&C) subsystem. Flight testing on Morpheus utilized ALHAT for safe landing site identification and ranking, followed by precise surface-relative navigation to the selected landing site. The successful autonomous, closed-loop flight demonstrations of the prototype ALHAT system have laid the foundation for the infusion of safe, precision landing capabilities into future planetary exploration missions.

A Low-Cost EEG System-Based Hybrid Brain-Computer Interface for Humanoid Robot Navigation and Recognition

PubMed Central

Choi, Bongjae; Jo, Sungho

2013-01-01

This paper describes a hybrid brain-computer interface (BCI) technique that combines the P300 potential, the steady state visually evoked potential (SSVEP), and event related de-synchronization (ERD) to solve a complicated multi-task problem consisting of humanoid robot navigation and control along with object recognition using a low-cost BCI system. Our approach enables subjects to control the navigation and exploration of a humanoid robot and recognize a desired object among candidates. This study aims to demonstrate the possibility of a hybrid BCI based on a low-cost system for a realistic and complex task. It also shows that the use of a simple image processing technique, combined with BCI, can further aid in making these complex tasks simpler. An experimental scenario is proposed in which a subject remotely controls a humanoid robot in a properly sized maze. The subject sees what the surrogate robot sees through visual feedback and can navigate the surrogate robot. While navigating, the robot encounters objects located in the maze. It then recognizes if the encountered object is of interest to the subject. The subject communicates with the robot through SSVEP and ERD-based BCIs to navigate and explore with the robot, and P300-based BCI to allow the surrogate robot recognize their favorites. Using several evaluation metrics, the performances of five subjects navigating the robot were quite comparable to manual keyboard control. During object recognition mode, favorite objects were successfully selected from two to four choices. Subjects conducted humanoid navigation and recognition tasks as if they embodied the robot. Analysis of the data supports the potential usefulness of the proposed hybrid BCI system for extended applications. This work presents an important implication for the future work that a hybridization of simple BCI protocols provide extended controllability to carry out complicated tasks even with a low-cost system. PMID:24023953

A low-cost EEG system-based hybrid brain-computer interface for humanoid robot navigation and recognition.

PubMed

Choi, Bongjae; Jo, Sungho

2013-01-01

This paper describes a hybrid brain-computer interface (BCI) technique that combines the P300 potential, the steady state visually evoked potential (SSVEP), and event related de-synchronization (ERD) to solve a complicated multi-task problem consisting of humanoid robot navigation and control along with object recognition using a low-cost BCI system. Our approach enables subjects to control the navigation and exploration of a humanoid robot and recognize a desired object among candidates. This study aims to demonstrate the possibility of a hybrid BCI based on a low-cost system for a realistic and complex task. It also shows that the use of a simple image processing technique, combined with BCI, can further aid in making these complex tasks simpler. An experimental scenario is proposed in which a subject remotely controls a humanoid robot in a properly sized maze. The subject sees what the surrogate robot sees through visual feedback and can navigate the surrogate robot. While navigating, the robot encounters objects located in the maze. It then recognizes if the encountered object is of interest to the subject. The subject communicates with the robot through SSVEP and ERD-based BCIs to navigate and explore with the robot, and P300-based BCI to allow the surrogate robot recognize their favorites. Using several evaluation metrics, the performances of five subjects navigating the robot were quite comparable to manual keyboard control. During object recognition mode, favorite objects were successfully selected from two to four choices. Subjects conducted humanoid navigation and recognition tasks as if they embodied the robot. Analysis of the data supports the potential usefulness of the proposed hybrid BCI system for extended applications. This work presents an important implication for the future work that a hybridization of simple BCI protocols provide extended controllability to carry out complicated tasks even with a low-cost system.

Application of aircraft navigation sensors to enhanced vision systems

NASA Technical Reports Server (NTRS)

Sweet, Barbara T.

1993-01-01

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.

An Effective Terrain Aided Navigation for Low-Cost Autonomous Underwater Vehicles.

PubMed

Zhou, Ling; Cheng, Xianghong; Zhu, Yixian; Dai, Chenxi; Fu, Jinbo

2017-03-25

Terrain-aided navigation is a potentially powerful solution for obtaining submerged position fixes for autonomous underwater vehicles. The application of terrain-aided navigation with high-accuracy inertial navigation systems has demonstrated meter-level navigation accuracy in sea trials. However, available sensors may be limited depending on the type of the mission. Such limitations, especially for low-grade navigation sensors, not only degrade the accuracy of traditional navigation systems, but further impact the ability to successfully employ terrain-aided navigation. To address this problem, a tightly-coupled navigation is presented to successfully estimate the critical sensor errors by incorporating raw sensor data directly into an augmented navigation system. Furthermore, three-dimensional distance errors are calculated, providing measurement updates through the particle filter for absolute and bounded position error. The development of the terrain aided navigation system is elaborated for a vehicle equipped with a non-inertial-grade strapdown inertial navigation system, a 4-beam Doppler Velocity Log range sensor and a sonar altimeter. Using experimental data for navigation performance evaluation in areas with different terrain characteristics, the experiment results further show that the proposed method can be successfully applied to the low-cost AUVs and significantly improves navigation performance.

An Effective Terrain Aided Navigation for Low-Cost Autonomous Underwater Vehicles

PubMed Central

Zhou, Ling; Cheng, Xianghong; Zhu, Yixian; Dai, Chenxi; Fu, Jinbo

2017-01-01

Terrain-aided navigation is a potentially powerful solution for obtaining submerged position fixes for autonomous underwater vehicles. The application of terrain-aided navigation with high-accuracy inertial navigation systems has demonstrated meter-level navigation accuracy in sea trials. However, available sensors may be limited depending on the type of the mission. Such limitations, especially for low-grade navigation sensors, not only degrade the accuracy of traditional navigation systems, but further impact the ability to successfully employ terrain-aided navigation. To address this problem, a tightly-coupled navigation is presented to successfully estimate the critical sensor errors by incorporating raw sensor data directly into an augmented navigation system. Furthermore, three-dimensional distance errors are calculated, providing measurement updates through the particle filter for absolute and bounded position error. The development of the terrain aided navigation system is elaborated for a vehicle equipped with a non-inertial-grade strapdown inertial navigation system, a 4-beam Doppler Velocity Log range sensor and a sonar altimeter. Using experimental data for navigation performance evaluation in areas with different terrain characteristics, the experiment results further show that the proposed method can be successfully applied to the low-cost AUVs and significantly improves navigation performance. PMID:28346346

33 CFR 62.31 - Special marks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Special marks. 62.31 Section 62.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.31 Special marks. Special...

33 CFR 62.25 - Lateral marks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lateral marks. 62.25 Section 62.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.25 Lateral marks. (a...

33 CFR 62.32 - Inland waters obstruction mark.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.32...

33 CFR 62.33 - Information and regulatory marks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Information and regulatory marks. 62.33 Section 62.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.33...

33 CFR 62.41 - Ranges.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids to...

33 CFR 62.29 - Isolated danger marks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Isolated danger marks. 62.29 Section 62.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.29 Isolated danger...

33 CFR 62.32 - Inland waters obstruction mark.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.32...

33 CFR 62.31 - Special marks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Special marks. 62.31 Section 62.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.31 Special marks. Special...

33 CFR 62.29 - Isolated danger marks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Isolated danger marks. 62.29 Section 62.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.29 Isolated danger...

33 CFR 62.33 - Information and regulatory marks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Information and regulatory marks. 62.33 Section 62.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.33...

33 CFR 62.31 - Special marks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Special marks. 62.31 Section 62.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.31 Special marks. Special...

33 CFR 62.41 - Ranges.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids to...

33 CFR 62.25 - Lateral marks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lateral marks. 62.25 Section 62.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.25 Lateral marks. (a...

33 CFR 62.33 - Information and regulatory marks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Information and regulatory marks. 62.33 Section 62.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.33...

33 CFR 62.25 - Lateral marks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lateral marks. 62.25 Section 62.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.25 Lateral marks. (a...

33 CFR 62.29 - Isolated danger marks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Isolated danger marks. 62.29 Section 62.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.29 Isolated danger...

33 CFR 62.31 - Special marks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Special marks. 62.31 Section 62.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.31 Special marks. Special...

33 CFR 62.32 - Inland waters obstruction mark.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.32...

33 CFR 62.37 - Lighthouses.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Lighthouses. 62.37 Section 62.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.37 Lighthouses. Lighthouses are...

33 CFR 62.37 - Lighthouses.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lighthouses. 62.37 Section 62.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.37 Lighthouses. Lighthouses are...

33 CFR 62.37 - Lighthouses.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Lighthouses. 62.37 Section 62.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.37 Lighthouses. Lighthouses are...

33 CFR 62.33 - Information and regulatory marks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Information and regulatory marks. 62.33 Section 62.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.33...

33 CFR 62.32 - Inland waters obstruction mark.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.32...

33 CFR 62.29 - Isolated danger marks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Isolated danger marks. 62.29 Section 62.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.29 Isolated danger...

33 CFR 62.41 - Ranges.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids to...

33 CFR 62.25 - Lateral marks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Lateral marks. 62.25 Section 62.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.25 Lateral marks. (a...

33 CFR 62.37 - Lighthouses.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Lighthouses. 62.37 Section 62.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.37 Lighthouses. Lighthouses are...

33 CFR 62.41 - Ranges.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids to...

33 CFR 62.37 - Lighthouses.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lighthouses. 62.37 Section 62.37 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.37 Lighthouses. Lighthouses are...

33 CFR 62.31 - Special marks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Special marks. 62.31 Section 62.31 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.31 Special marks. Special...

33 CFR 62.41 - Ranges.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Ranges. 62.41 Section 62.41 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.41 Ranges. Ranges are aids to...

33 CFR 62.29 - Isolated danger marks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Isolated danger marks. 62.29 Section 62.29 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.29 Isolated danger...

33 CFR 62.33 - Information and regulatory marks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Information and regulatory marks. 62.33 Section 62.33 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.33...

33 CFR 62.32 - Inland waters obstruction mark.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Inland waters obstruction mark. 62.32 Section 62.32 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.32...

33 CFR 62.25 - Lateral marks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Lateral marks. 62.25 Section 62.25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.25 Lateral marks. (a...

The UAV take-off and landing system used for small areas of mobile vehicles

NASA Astrophysics Data System (ADS)

Ren, Tian-Yu; Duanmu, Qing-Duo; Wu, Bo-Qi

2018-03-01

In order to realize an UAV formation cluster system based on the current GPS and the fault and insufficiency of Beidou integrated navigation system in strong jamming environment. Due to the impact of the compass on the plane crash, navigation system error caused by the mobile area to help reduce the need for large landing sites and not in the small fast moving area to achieve the reality of the landing. By using Strapdown inertial and all-optical system to form Composite UAV flight control system, the photoelectric composite strapdown inertial coupling is realized, and through the laser and microwave telemetry link compound communication mechanism, using all-optical strapdown inertial and visual navigation system to solve the deviation of take-off and landing caused by electromagnetic interference, all-optical bidirectional data link realizes two-way position correction of landing site and aircraft, thus achieves the accurate recovery of UAV formation cluster in the mobile narrow area which the traditional navigation system can't realize. This system is a set of efficient unmanned aerial vehicle Group Take-off/descending system, which is suitable for many tasks, and not only realizes the reliable continuous navigation under the complex electromagnetic interference environment, moreover, the intelligent flight and Take-off and landing of unmanned aerial vehicles relative to the fast moving and small recovery sites in complex electromagnetic interference environment can not only improve the safe operation rate of unmanned aerial vehicle, but also guarantee the operation safety of the aircraft, and the more has important social value for the application foreground of the aircraft.

Research on the error model of airborne celestial/inertial integrated navigation system

NASA Astrophysics Data System (ADS)

Zheng, Xiaoqiang; Deng, Xiaoguo; Yang, Xiaoxu; Dong, Qiang

2015-02-01

Celestial navigation subsystem of airborne celestial/inertial integrated navigation system periodically correct the positioning error and heading drift of the inertial navigation system, by which the inertial navigation system can greatly improve the accuracy of long-endurance navigation. Thus the navigation accuracy of airborne celestial navigation subsystem directly decides the accuracy of the integrated navigation system if it works for long time. By building the mathematical model of the airborne celestial navigation system based on the inertial navigation system, using the method of linear coordinate transformation, we establish the error transfer equation for the positioning algorithm of airborne celestial system. Based on these we built the positioning error model of the celestial navigation. And then, based on the positioning error model we analyze and simulate the positioning error which are caused by the error of the star tracking platform with the MATLAB software. Finally, the positioning error model is verified by the information of the star obtained from the optical measurement device in range and the device whose location are known. The analysis and simulation results show that the level accuracy and north accuracy of tracking platform are important factors that limit airborne celestial navigation systems to improve the positioning accuracy, and the positioning error have an approximate linear relationship with the level error and north error of tracking platform. The error of the verification results are in 1000m, which shows that the model is correct.

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

PubMed

Angrisano, Antonio; Petovello, Mark; Pugliano, Giovanni

2012-01-01

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.

Results of prototype software development for automation of shuttle proximity operations

NASA Technical Reports Server (NTRS)

Hiers, Hal; Olszweski, Oscar

1991-01-01

The effort involves demonstration of expert system technology application to Shuttle rendezvous operations in a high-fidelity, real-time simulation environment. The JSC Systems Engineering Simulator (SES) served as the test bed for the demonstration. Rendezvous applications were focused on crew procedures and monitoring of sensor health and trajectory status. Proximity operations applications were focused on monitoring, crew advisory, and control of the approach trajectory. Guidance, Navigation, and Control areas of emphasis included the approach, transition and stationkeeping guidance, and laser docking sensor navigation. Operator interface displays for monitor and control functions were developed. A rule-based expert system was developed to manage the relative navigation system/sensors for nominal operations and simple failure contingencies. Testing resulted in the following findings; (1) the developed guidance is applicable for operations with LVLH stabilized targets; (2) closing rates less than 0.05 feet per second are difficult to maintain due to the Shuttle translational/rotational cross-coupling; (3) automated operations result in reduced propellant consumption and plume impingement effects on the target as compared to manual operations; and (4) braking gates are beneficial for trajectory management. A versatile guidance design was demonstrated. An accurate proximity operations sensor/navigation system to provide relative attitude information within 30 feet is required and redesign of the existing Shuttle digital autopilot should be considered to reduce the cross-coupling effects. This activity has demonstrated the feasibility of automated Shuttle proximity operations with the Space Station Freedom. Indications are that berthing operations as well as docking can be supported.

33 CFR 62.35 - Mooring buoys.

Code of Federal Regulations, 2013 CFR

2013-07-01

....35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.35 Mooring buoys. Mooring... identification and to avoid confusion with aids to navigation. ...

33 CFR 62.35 - Mooring buoys.

Code of Federal Regulations, 2014 CFR

2014-07-01

....35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.35 Mooring buoys. Mooring... identification and to avoid confusion with aids to navigation. ...

33 CFR 62.35 - Mooring buoys.

Code of Federal Regulations, 2011 CFR

2011-07-01

....35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.35 Mooring buoys. Mooring... identification and to avoid confusion with aids to navigation. ...

33 CFR 62.35 - Mooring buoys.

Code of Federal Regulations, 2012 CFR

2012-07-01

....35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.35 Mooring buoys. Mooring... identification and to avoid confusion with aids to navigation. ...

33 CFR 62.35 - Mooring buoys.

Code of Federal Regulations, 2010 CFR

2010-07-01

....35 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.35 Mooring buoys. Mooring... identification and to avoid confusion with aids to navigation. ...

Advanced Endoscopic Navigation: Surgical Big Data, Methodology, and Applications.

PubMed

Luo, Xiongbiao; Mori, Kensaku; Peters, Terry M

2018-06-04

Interventional endoscopy (e.g., bronchoscopy, colonoscopy, laparoscopy, cystoscopy) is a widely performed procedure that involves either diagnosis of suspicious lesions or guidance for minimally invasive surgery in a variety of organs within the body cavity. Endoscopy may also be used to guide the introduction of certain items (e.g., stents) into the body. Endoscopic navigation systems seek to integrate big data with multimodal information (e.g., computed tomography, magnetic resonance images, endoscopic video sequences, ultrasound images, external trackers) relative to the patient's anatomy, control the movement of medical endoscopes and surgical tools, and guide the surgeon's actions during endoscopic interventions. Nevertheless, it remains challenging to realize the next generation of context-aware navigated endoscopy. This review presents a broad survey of various aspects of endoscopic navigation, particularly with respect to the development of endoscopic navigation techniques. First, we investigate big data with multimodal information involved in endoscopic navigation. Next, we focus on numerous methodologies used for endoscopic navigation. We then review different endoscopic procedures in clinical applications. Finally, we discuss novel techniques and promising directions for the development of endoscopic navigation.

Autonomous navigation and obstacle avoidance for unmanned surface vehicles

NASA Astrophysics Data System (ADS)

Larson, Jacoby; Bruch, Michael; Ebken, John

2006-05-01

The US Navy and other Department of Defense (DoD) and Department of Homeland Security (DHS) organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. In order for USVs to fill these roles, they must be capable of a relatively high degree of autonomous navigation. Space and Naval Warfare Systems Center, San Diego is developing core technologies required for robust USV operation in a real-world environment, primarily focusing on autonomous navigation, obstacle avoidance, and path planning.

Maximum Correntropy Unscented Kalman Filter for Ballistic Missile Navigation System based on SINS/CNS Deeply Integrated Mode.

PubMed

Hou, Bowen; He, Zhangming; Li, Dong; Zhou, Haiyin; Wang, Jiongqi

2018-05-27

Strap-down inertial navigation system/celestial navigation system ( SINS/CNS) integrated navigation is a high precision navigation technique for ballistic missiles. The traditional navigation method has a divergence in the position error. A deeply integrated mode for SINS/CNS navigation system is proposed to improve the navigation accuracy of ballistic missile. The deeply integrated navigation principle is described and the observability of the navigation system is analyzed. The nonlinearity, as well as the large outliers and the Gaussian mixture noises, often exists during the actual navigation process, leading to the divergence phenomenon of the navigation filter. The new nonlinear Kalman filter on the basis of the maximum correntropy theory and unscented transformation, named the maximum correntropy unscented Kalman filter, is deduced, and the computational complexity is analyzed. The unscented transformation is used for restricting the nonlinearity of the system equation, and the maximum correntropy theory is used to deal with the non-Gaussian noises. Finally, numerical simulation illustrates the superiority of the proposed filter compared with the traditional unscented Kalman filter. The comparison results show that the large outliers and the influence of non-Gaussian noises for SINS/CNS deeply integrated navigation is significantly reduced through the proposed filter.

33 CFR 62.27 - Safe water marks.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Safe water marks. 62.27 Section 62.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.27 Safe water marks. Safe...

Real-time visual mosaicking and navigation on the seafloor

NASA Astrophysics Data System (ADS)

Richmond, Kristof

Remote robotic exploration holds vast potential for gaining knowledge about extreme environments accessible to humans only with great difficulty. Robotic explorers have been sent to other solar system bodies, and on this planet into inaccessible areas such as caves and volcanoes. In fact, the largest unexplored land area on earth lies hidden in the airless cold and intense pressure of the ocean depths. Exploration in the oceans is further hindered by water's high absorption of electromagnetic radiation, which both inhibits remote sensing from the surface, and limits communications with the bottom. The Earth's oceans thus provide an attractive target for developing remote exploration capabilities. As a result, numerous robotic vehicles now routinely survey this environment, from remotely operated vehicles piloted over tethers from the surface to torpedo-shaped autonomous underwater vehicles surveying the mid-waters. However, these vehicles are limited in their ability to navigate relative to their environment. This limits their ability to return to sites with precision without the use of external navigation aids, and to maneuver near and interact with objects autonomously in the water and on the sea floor. The enabling of environment-relative positioning on fully autonomous underwater vehicles will greatly extend their power and utility for remote exploration in the furthest reaches of the Earth's waters---even under ice and under ground---and eventually in extraterrestrial liquid environments such as Europa's oceans. This thesis presents an operational, fielded system for visual navigation of underwater robotic vehicles in unexplored areas of the seafloor. The system does not depend on external sensing systems, using only instruments on board the vehicle. As an area is explored, a camera is used to capture images and a composite view, or visual mosaic, of the ocean bottom is created in real time. Side-to-side visual registration of images is combined with dead-reckoned navigation information in a framework allowing the creation and updating of large, locally consistent mosaics. These mosaics are used as maps in which the vehicle can navigate and localize itself with respect to points in the environment. The system achieves real-time performance in several ways. First, wherever possible, direct sensing of motion parameters is used in place of extracting them from visual data. Second, trajectories are chosen to enable a hierarchical search for side-to-side links which limits the amount of searching performed without sacrificing robustness. Finally, the map estimation is formulated as a sparse, linear information filter allowing rapid updating of large maps. The visual navigation enabled by the work in this thesis represents a new capability for remotely operated vehicles, and an enabling capability for a new generation of autonomous vehicles which explore and interact with remote, unknown and unstructured underwater environments. The real-time mosaic can be used on current tethered vehicles to create pilot aids and provide a vehicle user with situational awareness of the local environment and the position of the vehicle within it. For autonomous vehicles, the visual navigation system enables precise environment-relative positioning and mapping, without requiring external navigation systems, opening the way for ever-expanding autonomous exploration capabilities. The utility of this system was demonstrated in the field at sites of scientific interest using the ROVs Ventana and Tiburon operated by the Monterey Bay Aquarium Research Institute. A number of sites in and around Monterey Bay, California were mosaicked using the system, culminating in a complete imaging of the wreck site of the USS Macon , where real-time visual mosaics containing thousands of images were generated while navigating using only sensor systems on board the vehicle.

VLC-based indoor location awareness using LED light and image sensors

NASA Astrophysics Data System (ADS)

Lee, Seok-Ju; Yoo, Jong-Ho; Jung, Sung-Yoon

2012-11-01

Recently, indoor LED lighting can be considered for constructing green infra with energy saving and additionally providing LED-IT convergence services such as visible light communication (VLC) based location awareness and navigation services. For example, in case of large complex shopping mall, location awareness to navigate the destination is very important issue. However, the conventional navigation using GPS is not working indoors. Alternative location service based on WLAN has a problem that the position accuracy is low. For example, it is difficult to estimate the height exactly. If the position error of the height is greater than the height between floors, it may cause big problem. Therefore, conventional navigation is inappropriate for indoor navigation. Alternative possible solution for indoor navigation is VLC based location awareness scheme. Because indoor LED infra will be definitely equipped for providing lighting functionality, indoor LED lighting has a possibility to provide relatively high accuracy of position estimation combined with VLC technology. In this paper, we provide a new VLC based positioning system using visible LED lights and image sensors. Our system uses location of image sensor lens and location of reception plane. By using more than two image sensor, we can determine transmitter position less than 1m position error. Through simulation, we verify the validity of the proposed VLC based new positioning system using visible LED light and image sensors.

Analysis and design of a capsule landing system and surface vehicle control system for Mars exploration

NASA Technical Reports Server (NTRS)

Frederick, D. K.; Lashmet, P. K.; Sandor, G. N.; Shen, C. N.; Smith, E. J.; Yerazunis, S. W.

1971-01-01

Investigation of problems related to control of a mobile planetary vehicle according to a systematic plan for the exploration of Mars has been undertaken. Problem areas receiving attention include: (1) overall systems analysis; (2) vehicle configuration and dynamics; (3) toroidal wheel design and evaluation; (4) on-board navigation systems; (5) satellite-vehicle navigation systems; (6) obstacle detection systems; (7) terrain sensing, interpretation and modeling; (8) computer simulation of terrain sensor-path selection systems; and (9) chromatographic systems design concept studies. The specific tasks which have been undertaken are defined and the progress which has been achieved during the period July 1, 1971 to December 31, 1971 is summarized.

33 CFR 62.63 - Recommendations.

Code of Federal Regulations, 2013 CFR

2013-07-01

....63 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63 Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the...

33 CFR 62.63 - Recommendations.

Code of Federal Regulations, 2014 CFR

2014-07-01

....63 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63 Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the...

Optical surgical navigation system causes pulse oximeter malfunction.

PubMed

Satoh, Masaaki; Hara, Tetsuhito; Tamai, Kenji; Shiba, Juntaro; Hotta, Kunihisa; Takeuchi, Mamoru; Watanabe, Eiju

2015-01-01

An optical surgical navigation system is used as a navigator to facilitate surgical approaches, and pulse oximeters provide valuable information for anesthetic management. However, saw-tooth waves on the monitor of a pulse oximeter and the inability of the pulse oximeter to accurately record the saturation of a percutaneous artery were observed when a surgeon started an optical navigation system. The current case is thought to be the first report of this navigation system interfering with pulse oximetry. The causes of pulse jamming and how to manage an optical navigation system are discussed.

Gravity Gradiometry and Map Matching: An Aid to Aircraft Inertial Navigation Systems

DTIC Science & Technology

2010-03-01

improve its performance. In all of these cases, because information from two or more different navigation systems feeds into a navigation solution...GRAVITY GRADIOMETRY AND MAP MATCHING: AN AID TO AIRCRAFT INERTIAL NAVIGATION SYSTEMS THESIS...M06 GRAVITY GRADIOMETRY AND MAP MATCHING: AN AID TO AIRCRAFT INERTIAL NAVIGATION SYSTEMS THESIS Presented to the Faculty Department of

An Environment for Hardware-in-the-Loop Formation Navigation and Control Simulation

NASA Technical Reports Server (NTRS)

Burns, Rich

2004-01-01

Recent interest in formation flying satellite systems has spurred a considerable amount of research in the relative navigation and control of satellites. Development in this area has included new estimation and control algorithms as well as sensor and actuator development specifically geared toward the relative control problem. This paper describes a simulation facility, the Formation Flying Testbed (FFTB) at NASA's Goddard Space Flight Center, which allows engineers to test new algorithms for the formation flying problem with relevant GN&C hardware in a closed loop simulation. The FFTB currently supports the injection of GPS receiver hardware into the simulation loop, and support for satellite crosslink ranging technology is at a prototype stage. This closed-loop, hardware inclusive simulation capability permits testing of navigation and control software in the presence of the actual hardware with which the algorithms must interact. This capability provides the navigation or control developer with a perspective on how the algorithms perform as part of the closed-loop system. In this paper, the overall design and evolution of the FFTB are presented. Each component of the FFTB is then described in detail. Interfaces between the components of the FFTB are shown and the interfaces to and between navigation and control software are described in detail. Finally, an example of closed-loop formation control with GPS receivers in the loop is presented and results are analyzed.

33 CFR 62.27 - Safe water marks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Safe water marks. 62.27 Section 62.27 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.27 Safe water marks. Safe water marks indicate that there is...

Paediatric patient navigation models of care in Canada: An environmental scan.

PubMed

Luke, Alison; Doucet, Shelley; Azar, Rima

2018-05-01

(1) To provide other organizations with useful information when implementing paediatric navigation programs and (2) to inform the implementation of a navigation care centre in New Brunswick for children with complex health conditions. This environmental scan consisted of a literature review of published and grey literature for paediatric patient navigation programs across Canada. Additional programs were found following discussions with program coordinators and navigators. Interviews were conducted with key staff from each program and included questions related to patient condition; target population and location; method delivery; navigator background; and navigator roles. Data analysis included analysis of interviews and identification of common themes across the different programs. We interviewed staff from 19 paediatric navigation programs across Canada. Programs varied across a number of different themes, including: condition and disease type, program location (e.g., hospital or clinic), navigator background (e.g., registered nurse or peer/lay navigator) and method of delivery (e.g., phone or face-to-face). Overall, navigator roles are similar across all programs, including advocacy, education, support and assistance in accessing resources from both within and outside the health care system. This scan offers a road map of Canadian paediatric navigation programs. Knowledge learned from this scan will inform stakeholders who are either involved in the delivery of paediatric patient navigation programs or planning to implement such a program. Specifically, our scan informed the development of a navigation centre for children with complex health conditions in New Brunswick.

Navigation Aiding by a Hybrid Laser-Camera Motion Estimator for Micro Aerial Vehicles

PubMed Central

Atman, Jamal; Popp, Manuel; Ruppelt, Jan; Trommer, Gert F.

2016-01-01

Micro Air Vehicles (MAVs) equipped with various sensors are able to carry out autonomous flights. However, the self-localization of autonomous agents is mostly dependent on Global Navigation Satellite Systems (GNSS). In order to provide an accurate navigation solution in absence of GNSS signals, this article presents a hybrid sensor. The hybrid sensor is a deep integration of a monocular camera and a 2D laser rangefinder so that the motion of the MAV is estimated. This realization is expected to be more flexible in terms of environments compared to laser-scan-matching approaches. The estimated ego-motion is then integrated in the MAV’s navigation system. However, first, the knowledge about the pose between both sensors is obtained by proposing an improved calibration method. For both calibration and ego-motion estimation, 3D-to-2D correspondences are used and the Perspective-3-Point (P3P) problem is solved. Moreover, the covariance estimation of the relative motion is presented. The experiments show very accurate calibration and navigation results. PMID:27649203

The Black Kitchen Table Agreement: The Power of Silence during The Era of Trump

ERIC Educational Resources Information Center

Williams, Nathaniel Andrew

2017-01-01

The Black kitchen table has long served as a meeting place for Black families to discuss, debate, and critique issues related to the Black struggle. In particular, it was common for Black kitchen table conversations to talk about the nuances of navigating systems of legalized segregation and oppression, as well--and more recently--navigating the…

Proximity Operations Nano-Satellite Flight Demonstration (PONSFD) Rendezvous Proximity Operations Design and Trade Studies

NASA Astrophysics Data System (ADS)

Griesbach, J.; Westphal, J. J.; Roscoe, C.; Hawes, D. R.; Carrico, J. P.

2013-09-01

The Proximity Operations Nano-Satellite Flight Demonstration (PONSFD) program is to demonstrate rendezvous proximity operations (RPO), formation flying, and docking with a pair of 3U CubeSats. The program is sponsored by NASA Ames via the Office of the Chief Technologist (OCT) in support of its Small Spacecraft Technology Program (SSTP). The goal of the mission is to demonstrate complex RPO and docking operations with a pair of low-cost 3U CubeSat satellites using passive navigation sensors. The program encompasses the entire system evolution including system design, acquisition, satellite construction, launch, mission operations, and final disposal. The satellite is scheduled for launch in Fall 2015 with a 1-year mission lifetime. This paper provides a brief mission overview but will then focus on the current design and driving trade study results for the RPO mission specific processor and relevant ground software. The current design involves multiple on-board processors, each specifically tasked with providing mission critical capabilities. These capabilities range from attitude determination and control to image processing. The RPO system processor is responsible for absolute and relative navigation, maneuver planning, attitude commanding, and abort monitoring for mission safety. A low power processor running a Linux operating system has been selected for implementation. Navigation is one of the RPO processor's key tasks. This entails processing data obtained from the on-board GPS unit as well as the on-board imaging sensors. To do this, Kalman filters will be hosted on the processor to ingest and process measurements for maintenance of position and velocity estimates with associated uncertainties. While each satellite carries a GPS unit, it will be used sparsely to conserve power. As such, absolute navigation will mainly consist of propagating past known states, and relative navigation will be considered to be of greater importance. For relative observations, each spacecraft hosts 3 electro-optical sensors dedicated to imaging the companion satellite. The image processor will analyze the images to obtain estimates for range, bearing, and pose, with associated rates and uncertainties. These observations will be fed to the RPO processor's relative Kalman filter to perform relative navigation updates. This paper includes estimates for expected navigation accuracies for both absolute and relative position and velocity. Another key task for the RPO processor is maneuver planning. This includes automation to plan maneuvers to achieve a desired formation configuration or trajectory (including docking), as well as automation to safely react to potentially dangerous situations. This will allow each spacecraft to autonomously plan fuel-efficient maneuvers to achieve a desired trajectory as well as compute adjustment maneuvers to correct for thrusting errors. This paper discusses results from a trade study that has been conducted to examine maneuver targeting algorithms required on-board the spacecraft. Ground software will also work in conjunction with the on-board software to validate and approve maneuvers as necessary.

33 CFR 62.53 - Racons.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.53 Racons. (a) Aids to navigation may... non-laterally significant aids alike, the racon signal itself is for identification purposes only, and...

33 CFR 62.53 - Racons.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.53 Racons. (a) Aids to navigation may... non-laterally significant aids alike, the racon signal itself is for identification purposes only, and...

33 CFR 62.53 - Racons.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.53 Racons. (a) Aids to navigation may... non-laterally significant aids alike, the racon signal itself is for identification purposes only, and...

Visual Odometry for Autonomous Deep-Space Navigation

NASA Technical Reports Server (NTRS)

Robinson, Shane; Pedrotty, Sam

2016-01-01

Visual Odometry fills two critical needs shared by all future exploration architectures considered by NASA: Autonomous Rendezvous and Docking (AR&D), and autonomous navigation during loss of comm. To do this, a camera is combined with cutting-edge algorithms (called Visual Odometry) into a unit that provides accurate relative pose between the camera and the object in the imagery. Recent simulation analyses have demonstrated the ability of this new technology to reliably, accurately, and quickly compute a relative pose. This project advances this technology by both preparing the system to process flight imagery and creating an activity to capture said imagery. This technology can provide a pioneering optical navigation platform capable of supporting a wide variety of future missions scenarios: deep space rendezvous, asteroid exploration, loss-of-comm.

Autonomous RPRV Navigation, Guidance and Control

NASA Technical Reports Server (NTRS)

Johnston, Donald E.; Myers, Thomas T.; Zellner, John W.

1983-01-01

Dryden Flight Research Center has the responsibility for flight testing of advanced remotely piloted research vehicles (RPRV) to explore highly maneuverable aircraft technology, and to test advanced structural concepts, and related aeronautical technologies which can yield important research results with significant cost benefits. The primary purpose is to provide the preliminary design of an upgraded automatic approach and landing control system and flight director display to improve landing performance and reduce pilot workload. A secondary purpose is to determine the feasibility of an onboard autonomous navigation, orbit, and landing capability for safe vehicle recovery in the event of loss of telemetry uplink communication with the vehicles. The current RPRV approach and landing method, the proposed automatic and manual approach and autoland system, and an autonomous navigation, orbit, and landing system concept which is based on existing operational technology are described.

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

NASA Astrophysics Data System (ADS)

Xu, Peiliang

2017-06-01

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

Telecommunications, navigation and information management concept overview for the Space Exploration Initiative program

NASA Technical Reports Server (NTRS)

Bell, Jerome A.; Stephens, Elaine; Barton, Gregg

1991-01-01

An overview is provided of the Space Exploration Initiative (SEI) concepts for telecommunications, information systems, and navigation (TISN), and engineering and architecture issues are discussed. The SEI program data system is reviewed to identify mission TISN interfaces, and reference TISN concepts are described for nominal, degraded, and mission-critical data services. The infrastructures reviewed include telecommunications for robotics support, autonomous navigation without earth-based support, and information networks for tracking and data acquisition. Four options for TISN support architectures are examined which relate to unique SEI exploration strategies. Detailed support estimates are given for: (1) a manned stay on Mars; (2) permanent lunar and Martian settlements; short-duration missions; and (4) systematic exploration of the moon and Mars.

Navigability Potential of Washington Rivers and Streams Determined with Hydraulic Geometry and a Geographic Information System

USGS Publications Warehouse

Magirl, Christopher S.; Olsen, Theresa D.

2009-01-01

Using discharge and channel geometry measurements from U.S. Geological Survey streamflow-gaging stations and data from a geographic information system, regression relations were derived to predict river depth, top width, and bottom width as a function of mean annual discharge for rivers in the State of Washington. A new technique also was proposed to determine bottom width in channels, a parameter that has received relatively little attention in the geomorphology literature. These regression equations, when combined with estimates of mean annual discharge available in the National Hydrography Dataset, enabled the prediction of hydraulic geometry for any stream or river in the State of Washington. Predictions of hydraulic geometry can then be compared to thresholds established by the Washington State Department of Natural Resources to determine navigability potential of rivers. Rivers with a mean annual discharge of 1,660 cubic feet per second or greater are 'probably navigable' and rivers with a mean annual discharge of 360 cubic feet per second or less are 'probably not navigable'. Variance in the dataset, however, leads to a relatively wide range of prediction intervals. For example, although the predicted hydraulic depth at a mean annual discharge of 1,660 cubic feet per second is 3.5 feet, 90-percent prediction intervals indicate that the actual hydraulic depth may range from 1.8 to 7.0 feet. This methodology does not determine navigability - a legal concept determined by federal common law - instead, this methodology is a tool for predicting channel depth, top width, and bottom width for rivers and streams in Washington.

Intraformation positioning system

NASA Astrophysics Data System (ADS)

Sheldon, Stuart; Zadzora, Timothy

1996-05-01

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

33 CFR 62.23 - Beacons and buoys.

Code of Federal Regulations, 2010 CFR

2010-07-01

... navigation. The primary components of the U.S. Aids to Navigation System are beacons and buoys. (b) Beacons are aids to navigation structures which are permanently fixed to the earth's surface. They range from... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.23 Beacons and buoys. (a...

33 CFR 62.23 - Beacons and buoys.

Code of Federal Regulations, 2011 CFR

2011-07-01

... navigation. The primary components of the U.S. Aids to Navigation System are beacons and buoys. (b) Beacons are aids to navigation structures which are permanently fixed to the earth's surface. They range from... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.23 Beacons and buoys. (a...

33 CFR 62.23 - Beacons and buoys.

Code of Federal Regulations, 2013 CFR

2013-07-01

... navigation. The primary components of the U.S. Aids to Navigation System are beacons and buoys. (b) Beacons are aids to navigation structures which are permanently fixed to the earth's surface. They range from... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.23 Beacons and buoys. (a...

33 CFR 62.23 - Beacons and buoys.

Code of Federal Regulations, 2014 CFR

2014-07-01

... navigation. The primary components of the U.S. Aids to Navigation System are beacons and buoys. (b) Beacons are aids to navigation structures which are permanently fixed to the earth's surface. They range from... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.23 Beacons and buoys. (a...

33 CFR 62.23 - Beacons and buoys.

Code of Federal Regulations, 2012 CFR

2012-07-01

... navigation. The primary components of the U.S. Aids to Navigation System are beacons and buoys. (b) Beacons are aids to navigation structures which are permanently fixed to the earth's surface. They range from... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.23 Beacons and buoys. (a...

Development of a chronic kidney disease patient navigator program.

PubMed

Jolly, Stacey E; Navaneethan, Sankar D; Schold, Jesse D; Arrigain, Susana; Konig, Victoria; Burrucker, Yvette K; Hyland, Jennifer; Dann, Priscilla; Tucky, Barbara H; Sharp, John W; Nally, Joseph V

2015-05-03

Chronic Kidney Disease (CKD) is a public health problem and there is a scarcity of type 2 CKD translational research that incorporates educational tools. Patient navigators have been shown to be effective at reducing disparities and improving outcomes in the oncology field. We describe the creation of a CKD Patient Navigator program designed to help coordinate care, address system-barriers, and educate/motivate patients. The conceptual framework for the CKD Patient Navigator Program is rooted in the Chronic Care Model that has a main goal of high-quality chronic disease management. Our established multidisciplinary CKD research team enlisted new members from information technology and data management to help create the program. It encompassed three phases: hiring, training, and implementation. For hiring, we wanted a non-medical or lay person with a college degree that possessed strong interpersonal skills and experience in a service-orientated field. For training, there were three key areas: general patient navigator training, CKD education, and electronic health record (EHR) training. For implementation, we defined barriers of care and created EHR templates for which pertinent study data could be extracted. We have hired two CKD patient navigators who will be responsible for navigating CKD patients enrolled in a clinical trial. They have undergone training in general patient navigation, specific CKD education through directed readings and clinical shadowing, as well as EHR and other patient related privacy and research training. The need for novel approaches like our CKD patient navigator program designed to impact CKD care is vital and should utilize team-based care and health information technology given the changing landscape of our health systems.

Science Benefits of Onboard Spacecraft Navigation

NASA Technical Reports Server (NTRS)

Cangahuala, Al; Bhaskaran, Shyam; Owen, Bill

2012-01-01

Primitive bodies (asteroids and comets), which have remained relatively unaltered since their formation, are important targets for scientific missions that seek to understand the evolution of the solar system. Often the first step is to fly by these bodies with robotic spacecraft. The key to maximizing data returns from these flybys is to determine the spacecraft trajectory relative to the target body-in short, navigate the spacecraft- with sufficient accuracy so that the target is guaranteed to be in the instruments' field of view. The most powerful navigation data in these scenarios are images taken by the spacecraft of the target against a known star field (onboard astrometry). Traditionally, the relative trajectory of the spacecraft must be estimated hours to days in advance using images collected by the spacecraft. This is because of (1)!the long round-trip light times between the spacecraft and the Earth and (2)!the time needed to downlink and process navigation data on the ground, make decisions based on the result, and build and uplink instrument pointing sequences from the results. The light time and processing time compromise navigation accuracy considerably, because there is not enough time to use more accurate data collected closer to the target-such data are more accurate because the angular capability of the onboard astrometry is essentially constant as the distance to the target decreases, resulting in better "plane-of- sky" knowledge of the target. Excellent examples of these timing limitations are high-speed comet encounters. Comets are difficult to observe up close; their orbits often limit scientists to brief, rapid flybys, and their coma further restricts viewers from seeing the nucleus in any detail, unless they can view the nucleus at close range. Comet nuclei details are typically discernable for much shorter durations than the roundtrip light time to Earth, so robotic spacecraft must be able to perform onboard navigation. This onboard navigation can be accomplished through a self- contained system that by eliminating light time restrictions dramatically improves the relative trajectory knowledge and control and subsequently increases the amount of quality data collected. Flybys are one-time events, so the system's underlying algorithms and software must be extremely robust. The autonomous software must also be able to cope with the unknown size, shape, and orientation of the previously unseen comet nucleus. Furthermore, algorithms must be reliable in the presence of imperfections and/or damage to onboard cameras accrued after many years of deep-space operations. The AutoNav operational flight software packages, developed by scientists at the Jet Propulsion Laboratory (JPL) under contract with NASA, meet all these requirements. They have been directly responsible for the successful encounters on all of NASA's close-up comet-imaging missions (see Figure !1). AutoNav is the only system to date that has autonomously tracked comet nuclei during encounters and performed autonomous interplanetary navigation. AutoNav has enabled five cometary flyby missions (Table!1) residing on four NASA spacecraft provided by three different spacecraft builders. Using this software, missions were able to process a combined total of nearly 1000 images previously unseen by humans. By eliminating the need to navigate spacecraft from Earth, the accuracy gained by AutoNav during flybys compared to ground-based navigation is about 1!order of magnitude in targeting and 2!orders of magnitude in time of flight. These benefits ensure that pointing errors do not compromise data gathered during flybys. In addition, these benefits can be applied to flybys of other solar system objects, flybys at much slower relative velocities, mosaic imaging campaigns, and other proximity activities (e.g., orbiting, hovering, and descent/ascent).

33 CFR 62.54 - Ownership identification.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 62.54 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.54 Ownership identification. Ownership identification on private or state aids to navigation is permitted so long as it does...

33 CFR 62.54 - Ownership identification.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 62.54 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.54 Ownership identification. Ownership identification on private or state aids to navigation is permitted so long as it does...

33 CFR 62.54 - Ownership identification.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 62.54 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.54 Ownership identification. Ownership identification on private or state aids to navigation is permitted so long as it does...

33 CFR 62.54 - Ownership identification.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Section 62.54 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.54 Ownership identification. Ownership identification on private or state aids to navigation is permitted so long as it does...

33 CFR 62.54 - Ownership identification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 62.54 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.54 Ownership identification. Ownership identification on private or state aids to navigation is permitted so long as it does...

33 CFR 62.45 - Light characteristics.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and range...

33 CFR 62.45 - Light characteristics.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and range...

33 CFR 62.45 - Light characteristics.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and range...

33 CFR 62.45 - Light characteristics.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and range...

33 CFR 62.45 - Light characteristics.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Light characteristics. 62.45... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.45 Light characteristics. (a) Lights on aids to navigation are differentiated by color and rhythm. Lighthouses and range...

Amblypygids: Model Organisms for the Study of Arthropod Navigation Mechanisms in Complex Environments?

PubMed Central

Wiegmann, Daniel D.; Hebets, Eileen A.; Gronenberg, Wulfila; Graving, Jacob M.; Bingman, Verner P.

2016-01-01

Navigation is an ideal behavioral model for the study of sensory system integration and the neural substrates associated with complex behavior. For this broader purpose, however, it may be profitable to develop new model systems that are both tractable and sufficiently complex to ensure that information derived from a single sensory modality and path integration are inadequate to locate a goal. Here, we discuss some recent discoveries related to navigation by amblypygids, nocturnal arachnids that inhabit the tropics and sub-tropics. Nocturnal displacement experiments under the cover of a tropical rainforest reveal that these animals possess navigational abilities that are reminiscent, albeit on a smaller spatial scale, of true-navigating vertebrates. Specialized legs, called antenniform legs, which possess hundreds of olfactory and tactile sensory hairs, and vision appear to be involved. These animals also have enormous mushroom bodies, higher-order brain regions that, in insects, integrate contextual cues and may be involved in spatial memory. In amblypygids, the complexity of a nocturnal rainforest may impose navigational challenges that favor the integration of information derived from multimodal cues. Moreover, the movement of these animals is easily studied in the laboratory and putative neural integration sites of sensory information can be manipulated. Thus, amblypygids could serve as model organisms for the discovery of neural substrates associated with a unique and potentially sophisticated navigational capability. The diversity of habitats in which amblypygids are found also offers an opportunity for comparative studies of sensory integration and ecological selection pressures on navigation mechanisms. PMID:27014008

Area navigation and required navigation performance procedures and depictions

DOT National Transportation Integrated Search

2012-09-30

Area navigation (RNAV) and required navigation performance (RNP) procedures are fundamental to the implementation of a performance based navigation (PBN) system, which is a key enabling technology for the Next Generation Air Transportation System (Ne...

Design of all-weather celestial navigation system

NASA Astrophysics Data System (ADS)

Sun, Hongchi; Mu, Rongjun; Du, Huajun; Wu, Peng

2018-03-01

In order to realize autonomous navigation in the atmosphere, an all-weather celestial navigation system is designed. The research of celestial navigation system include discrimination method of comentropy and the adaptive navigation algorithm based on the P value. The discrimination method of comentropy is studied to realize the independent switching of two celestial navigation modes, starlight and radio. Finally, an adaptive filtering algorithm based on P value is proposed, which can greatly improve the disturbance rejection capability of the system. The experimental results show that the accuracy of the three axis attitude is better than 10″, and it can work all weather. In perturbation environment, the position accuracy of the integrated navigation system can be increased 20% comparing with the traditional method. It basically meets the requirements of the all-weather celestial navigation system, and it has the ability of stability, reliability, high accuracy and strong anti-interference.

Comparison of accuracy and safety of the SEVEN and the Navigator continuous glucose monitoring systems.

PubMed

Garg, Satish K; Smith, James; Beatson, Christie; Lopez-Baca, Benita; Voelmle, Mary; Gottlieb, Peter A

2009-02-01

This study evaluated the accuracy and safety of two continuous glucose monitoring (CGM) systems, the SEVEN (DexCom, San Diego, CA) and the Navigator (Abbott Diabetes Care, Alameda, CA), with the YSI laboratory measurements of blood glucose (blood glucose meter manufactured by YSI, Yellow Springs, OH), when worn concurrently in adults with type 1 diabetes. Fourteen subjects with type 1 diabetes, 33 +/- 6 (mean +/- SD) years old, were enrolled in this study. All subjects wore both sensors concurrently over three consecutive 5-day CGM sessions (15-day wear). On Days 5, 10, and 15, subjects participated in an 8-h in-clinic session where measurements from the CGM systems were collected and compared with YSI measurements every 15 min. At the end of Day 5 and 10 in-clinic sessions, the sensors were removed, and new sensors were inserted for the following CGM session despite the SEVEN system's recommended use for up to 7 days. The mean absolute relative difference (ARD) for the two CGM devices versus YSI was not different: 16.8% and 16.1% for SEVEN and Navigator, respectively (P = 0.38). In the hypoglycemic region (YSI value <80 mg/dL), the mean ARD for SEVEN was lower than for Navigator (21.5% vs. 29.8%, respectively; P = 0.001). The data analyses were similar when compared with self-monitoring of blood glucose (SMBG) values. Thirteen additional Navigator replacement devices were issued compared to two for the SEVEN. A total of three versus 14 skin reactions were reported with the SEVEN and Navigator insertion area, respectively. Glucose measurements with the SEVEN and Navigator were found to be similar compared with YSI and SMBG measurements, with the exception of the hypoglycemic range where the SEVEN performed better. However, the Navigator caused more skin area reactions.

Correlated-Data Fusion and Cooperative Aiding in GNSS-Stressed or Denied Environments

NASA Astrophysics Data System (ADS)

Mokhtarzadeh, Hamid

A growing number of applications require continuous and reliable estimates of position, velocity, and orientation. Price requirements alone disqualify most traditional navigation or tactical-grade sensors and thus navigation systems based on automotive or consumer-grade sensors aided by Global Navigation Satellite Systems (GNSS), like the Global Positioning System (GPS), have gained popularity. The heavy reliance on GPS in these navigation systems is a point of concern and has created interest in alternative or back-up navigation systems to enable robust navigation through GPS-denied or stressed environments. This work takes advantage of current trends for increased sensing capabilities coupled with multilayer connectivity to propose a cooperative navigation-based aiding system as a means to limit dead reckoning error growth in the absence of absolute measurements like GPS. Each vehicle carries a dead reckoning navigation system which is aided by relative measurements, like range, to neighboring vehicles together with information sharing. Detailed architectures and concepts of operation are described for three specific applications: commercial aviation, Unmanned Aerial Vehicles (UAVs), and automotive applications. Both centralized and decentralized implementations of cooperative navigation-based aiding systems are described. The centralized system is based on a single Extended Kalman Filter (EKF). A decentralized implementation suited for applications with very limited communication bandwidth is discussed in detail. The presence of unknown correlation between the a priori state and measurement errors makes the standard Kalman filter unsuitable. Two existing estimators for handling this unknown correlation are Covariance Intersection (CI) and Bounded Covariance Inflation (BCInf) filters. A CI-based decentralized estimator suitable for decentralized cooperative navigation implementation is proposed. A unified derivation is presented for the Kalman filter, CI filter, and BCInf filter measurement update equations. Furthermore, characteristics important to the proper implementation of CI and BCInf in practice are discussed. A new covariance normalization step is proposed as necessary to properly apply CI or BCInf. Lastly, both centralized and decentralized implementations of cooperative aiding are analyzed and evaluated using experimental data in the three applications. In the commercial aviation study aircraft are simulated to use their Automatic Dependent Surveillance - Broadcast (ADS-B) and Traffic Collision Avoidance System (TCAS) systems to cooperatively aid their on board INS during a 60 min GPS outage in the national airspace. An availability study of cooperative navigation as proposed in this work around representative United States airports is performed. Availabilities between 70-100% were common at major airports like LGA and MSP in a 30 nmi radius around the airport during morning to evening hours. A GPS-denied navigation system for small UAVs based on cooperative information sharing is described. Experimentally collected flight data from 7 small UAV flights are played-back to evaluate the performance of the navigation system. The results show that the most effective of the architectures can lead to 5+ minutes of navigation without GPS maintaining position errors less than 200 m (1-sigma). The automotive case study considers 15 minutes of automotive traffic (2,000 + vehicles) driving through a half-mile stretch of highway without access to GPS. Automotive radar coupled with Dedicated Short Range Communication (DSRC) protocol are used to implement cooperative aiding to a low-cost 2-D INS on board each vehicle. The centralized system achieves an order of magnitude reduction in uncertainty by aggressively aiding the INS on board each vehicle. The proposed CI-based decentralized estimator is demonstrated to be conservative and maintain consistency. A quantitative analysis of bandwidth requirements shows that the proposed decentralized estimator falls comfortably within modern connectivity capabilities. A naive implementation of the high-performance centralized estimator is also achievable, but it was demonstrated to be burdensome, nearing the bandwidth limits.

a New Survey on Self-Tuning Integrated Low-Cost Gps/ins Vehicle Navigation System in Harsh Environment

NASA Astrophysics Data System (ADS)

Navidi, N.; Landry, R., Jr.

2015-08-01

Nowadays, Global Positioning System (GPS) receivers are aided by some complementary radio navigation systems and Inertial Navigation Systems (INS) to obtain more accuracy and robustness in land vehicular navigation. Extended Kalman Filter (EKF) is an acceptable conventional method to estimate the position, the velocity, and the attitude of the navigation system when INS measurements are fused with GPS data. However, the usage of the low-cost Inertial Measurement Units (IMUs) based on the Micro-Electro-Mechanical Systems (MEMS), for the land navigation systems, reduces the precision and stability of the navigation system due to their inherent errors. The main goal of this paper is to provide a new model for fusing low-cost IMU and GPS measurements. The proposed model is based on EKF aided by Fuzzy Inference Systems (FIS) as a promising method to solve the mentioned problems. This model considers the parameters of the measurement noise to adjust the measurement and noise process covariance. The simulation results show the efficiency of the proposed method to reduce the navigation system errors compared with EKF.

Localization and Mapping Using a Non-Central Catadioptric Camera System

NASA Astrophysics Data System (ADS)

Khurana, M.; Armenakis, C.

2018-05-01

This work details the development of an indoor navigation and mapping system using a non-central catadioptric omnidirectional camera and its implementation for mobile applications. Omnidirectional catadioptric cameras find their use in navigation and mapping of robotic platforms, owing to their wide field of view. Having a wider field of view, or rather a potential 360° field of view, allows the system to "see and move" more freely in the navigation space. A catadioptric camera system is a low cost system which consists of a mirror and a camera. Any perspective camera can be used. A platform was constructed in order to combine the mirror and a camera to build a catadioptric system. A calibration method was developed in order to obtain the relative position and orientation between the two components so that they can be considered as one monolithic system. The mathematical model for localizing the system was determined using conditions based on the reflective properties of the mirror. The obtained platform positions were then used to map the environment using epipolar geometry. Experiments were performed to test the mathematical models and the achieved location and mapping accuracies of the system. An iterative process of positioning and mapping was applied to determine object coordinates of an indoor environment while navigating the mobile platform. Camera localization and 3D coordinates of object points obtained decimetre level accuracies.

Exploring creative activity: a software environment for multimedia systems

NASA Astrophysics Data System (ADS)

Farrett, Peter W.; Jardine, David A.

1992-03-01

This paper examines various issues related to the theory, design, and implementation of a system that supports creative activity for a multimedia environment. The system incorporates artificial intelligence notions to acquire concepts of the problem domain. This paper investigates this environment by considering a model that is a basis for a system, which supports a history of user interaction. A multimedia system that supports creative activity is problematic. It must function as a tool allowing users to experiment dynamically with their own creative reasoning process--a very nebulous task environment. It should also support the acquisition of domain knowledge so that empirical observation can be further evaluated. This paper aims to illustrate that via the reuse of domain-specific knowledge, closely related ideas can be quickly developed. This approach is useful in the following sense: Multimedia navigational systems hardcode referential links with respect to a web or network. Although users can access or control navigation in a nonlinear (static) manner, these referential links are 'frozen' and can not capture their creative actions, which are essential in tutoring or learning applications. This paper describes a multimedia assistant based on the notion of knowledge- links, which allows users to navigate through creative information in a nonlinear (dynamic) fashion. A selection of prototype code based on object-oriented techniques and logic programming partially demonstrates this.

Method, accuracy and limitation of computer interaction in the operating room by a navigated surgical instrument.

PubMed

Hurka, Florian; Wenger, Thomas; Heininger, Sebastian; Lueth, Tim C

2011-01-01

This article describes a new interaction device for surgical navigation systems--the so-called navigation mouse system. The idea is to use a tracked instrument of a surgical navigation system like a pointer to control the software. The new interaction system extends existing navigation systems with a microcontroller-unit. The microcontroller-unit uses the existing communication line to extract the needed 3D-information of an instrument to calculate positions analogous to the PC mouse cursor and click events. These positions and events are used to manipulate the navigation system. In an experimental setup the reachable accuracy with the new mouse system is shown.

Femur-mounted navigation system for the arthroscopic treatment of femoroacetabular impingement

NASA Astrophysics Data System (ADS)

Park, S. H.; Hwang, D. S.; Yoon, Y. S.

2013-07-01

Femoroacetabular impingement stems from an abnormal shape of the acetabulum and proximal femur. It is treated by resection of damaged soft tissue and by the shaping of bone to resemble normal features. The arthroscopic treatment of femoroacetabular impingement has many advantages, including minimal incisions, rapid recovery, and less pain. However, in some cases, revision is needed owing to the insufficient resection of damaged bone from a misreading of the surgical site. The limited view of arthroscopy is the major reason for the complications. In this research, a navigation method for the arthroscopic treatment of femoroacetabular impingement is developed. The proposed navigation system consists of femur attachable measurement device and user interface. The bone mounted measurement devices measure points on head-neck junction for registration and position of surgical instrument. User interface shows the three-dimensional model of patient's femur and surgical instrument position that is tracked by measurement device. Surgeon can know the three-dimensional anatomical structure of hip joint and surgical instrument position on surgical site using navigation system. Surface registration was used to obtain relation between patient's coordinate at the surgical site and coordinate of three-dimensional model of femur. In this research, we evaluated the proposed navigation system using plastic model bone. It is expected that the surgical tool tracking position accuracy will be less than 1 mm.

Implementation of a vector-based tracking loop receiver in a pseudolite navigation system.

PubMed

So, Hyoungmin; Lee, Taikjin; Jeon, Sanghoon; Kim, Chongwon; Kee, Changdon; Kim, Taehee; Lee, Sanguk

2010-01-01

We propose a vector tracking loop (VTL) algorithm for an asynchronous pseudolite navigation system. It was implemented in a software receiver and experiments in an indoor navigation system were conducted. Test results show that the VTL successfully tracks signals against the near-far problem, one of the major limitations in pseudolite navigation systems, and could improve positioning availability by extending pseudolite navigation coverage.

Institute of Navigation, Annual Meeting, 47th, Williamsburg, VA, June 10-12, 1991, Proceedings

NASA Astrophysics Data System (ADS)

1991-11-01

The present volume of navigation and exploration discusses space exploration, mapping and geodesy, aircraft navigation, undersea navigation, land and vehicular location, international and legal aspects of navigation, the history of navigation technology and applications, Loran development and implementation, GPS and GLONASS developments, and search and rescue. Topics addressed include stabilization of low orbiting spacecraft using GPS, the employment of laser navigation for automatic rendezvous and docking systems, enhanced pseudostatic processing, and the expanding role of sensor fusion. Attention is given to a gravity-aided inertial navigation system, recent developments in aviation products liability and navigation, the ICAO future air navigation system, and Loran's implementation in NAS. Also discussed are Inmarsat integrated navigation/communication activities, the GPS program status, the evolution of military GPS technology into the Navcore V receiver engine, and Sarsat location algorithms.

A dataset on human navigation strategies in foreign networked systems

PubMed Central

Kőrösi, Attila; Csoma, Attila; Rétvári, Gábor; Heszberger, Zalán; Bíró, József; Tapolcai, János; Pelle, István; Klajbár, Dávid; Novák, Márton; Halasi, Valentina; Gulyás, András

2018-01-01

Humans are involved in various real-life networked systems. The most obvious examples are social and collaboration networks but the language and the related mental lexicon they use, or the physical map of their territory can also be interpreted as networks. How do they find paths between endpoints in these networks? How do they obtain information about a foreign networked world they find themselves in, how they build mental model for it and how well they succeed in using it? Large, open datasets allowing the exploration of such questions are hard to find. Here we report a dataset collected by a smartphone application, in which players navigate between fixed length source and destination English words step-by-step by changing only one letter at a time. The paths reflect how the players master their navigation skills in such a foreign networked world. The dataset can be used in the study of human mental models for the world around us, or in a broader scope to investigate the navigation strategies in complex networked systems. PMID:29533391

NASA Precision Landing Technologies Completes Initial Flight Tests on Vertical Testbed Rocket

NASA Image and Video Library

2017-04-19

This 2-minute, 40-second video shows how over the past 5 weeks, NASA and Masten Space Systems teams have prepared for and conducted sub-orbital rocket flight tests of next-generation lander navigation technology through the CoOperative Blending of Autonomous Landing Technologies (COBALT) project. The COBALT payload was integrated onto Masten’s rocket, Xodiac. The Xodiac vehicle used the Global Positioning System (GPS) for navigation during this first campaign, which was intentional to verify and refine COBALT system performance. The joint teams conducted numerous ground verification tests, made modifications in the process, practiced and refined operations’ procedures, conducted three tether tests, and have now flown two successful free flights. This successful, collaborative campaign has provided the COBALT and Xodiac teams with the valuable performance data needed to refine the systems and prepare them for the second flight test campaign this summer when the COBALT system will navigate the Xodiac rocket to a precision landing. The technologies within COBALT provide a spacecraft with knowledge during entry, descent, and landing that enables it to precisely navigate and softly land close to surface locations that have been previously too risky to target with current capabilities. The technologies will enable future exploration destinations on Mars, the moon, Europa, and other planets and moons. The two primary navigation components within COBALT include the Langley Research Center’s Navigation Doppler Lidar, which provides ultra-precise velocity and line-of-sight range measurements, and Jet Propulsion Laboratory’s Lander Vision System (LVS), which provides navigation estimates relative to an existing surface map. The integrated system is being flight tested onboard a Masten suborbital rocket vehicle called Xodiac. The COBALT project is led by the Johnson Space Center, with funding provided through the Game Changing Development, Flight Opportunities program, and Advanced Exploration Systems programs. Based at NASA’s Armstrong Flight Research Center in Edwards, CA, the Flight Opportunities program funds technology development flight tests on commercial suborbital space providers of which Masten is a vendor. The program has previously tested the LVS on the Masten rocket and validated the technology for the Mars 2020 rover.

Using multiple IMUs in a stacked filter configuration for calibration and fine alignment

NASA Astrophysics Data System (ADS)

El-Osery, Aly; Bruder, Stephen; Wedeward, Kevin

2018-05-01

Determination of a vehicle or person's position and/or orientation is a critical task for a multitude of applications ranging from automated cars and first responders to missiles and fighter jets. Most of these applications rely primarily on global navigation satellite systems, e.g., GPS, which are highly vulnerable to degradation whether by environmental factors or malicious actions. The use of inertial navigation techniques has been shown to provide increased reliability of navigation systems in these situations. Due to advances in MEMS technology and processing capabilities, the use of small and low-cost inertial measurement units (IMUs) are becoming increasingly feasible, which results in small size, weight and power (SWaP) solutions. A known limitation of MEMS IMUs are errors that causes the navigation solution to drift; furthermore, calibration and initialization are challenging tasks. In this paper, we investigate the use of multiple IMUs to aid in calibrating the navigation system and obtaining accurate initialization by performing fine alignment. By using a centralized filter, physical constraints between the multiple IMUs on a rigid body are leveraged to provide relative updates, which in turn aids in the estimation of the individual biases and scale-factors. Developed algorithms will be validated through simulation and actual measurements using low-cost IMUs.

33 CFR 146.105 - General alarm system.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manned facility must have a general alarm system. When operated, this system shall be audible in all... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false General alarm system. 146.105 Section 146.105 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED...

Interference and deception detection technology of satellite navigation based on deep learning

NASA Astrophysics Data System (ADS)

Chen, Weiyi; Deng, Pingke; Qu, Yi; Zhang, Xiaoguang; Li, Yaping

2017-10-01

Satellite navigation system plays an important role in people's daily life and war. The strategic position of satellite navigation system is prominent, so it is very important to ensure that the satellite navigation system is not disturbed or destroyed. It is a critical means to detect the jamming signal to avoid the accident in a navigation system. At present, the detection technology of jamming signal in satellite navigation system is not intelligent , mainly relying on artificial decision and experience. For this issue, the paper proposes a method based on deep learning to monitor the interference source in a satellite navigation. By training the interference signal data, and extracting the features of the interference signal, the detection sys tem model is constructed. The simulation results show that, the detection accuracy of our detection system can reach nearly 70%. The method in our paper provides a new idea for the research on intelligent detection of interference and deception signal in a satellite navigation system.

The DGPS based navigation and positioning system of the Helsinki University of Technology Short SC7 Skyvan research aircraft

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

Tauriainen, S.; Ahola, P.; Hallikainen, M.

1996-10-01

The typical airborne remote sensing measurements conducted by the Helsinki University of Technology laboratory of space technology require very precise navigation over the selected measurement sites. This means that both system performance as far as positioning is concerned and the actual flight track of the aircraft has to be within 10 meters. To meet these requirements, a custom made navigation system was designed and installed in the SHORT SC7 Skyvan research aircraft of the Helsinki University of Technology. The system is based on the Finnish national Differential GPS network providing positioning accuracy within a few meters within Finland. For pilotmore » guidance, a graphical user interface with mission specific software is used to give the pilots an overview of the relative position and orientation to the measurement target. In addition, the system is used to synchronize the scientific instruments and record the actual flight track. 2 refs., 2 figs.« less

Positioning accuracy in a registration-free CT-based navigation system

NASA Astrophysics Data System (ADS)

Brandenberger, D.; Birkfellner, W.; Baumann, B.; Messmer, P.; Huegli, R. W.; Regazzoni, P.; Jacob, A. L.

2007-12-01

In order to maintain overall navigation accuracy established by a calibration procedure in our CT-based registration-free navigation system, the CT scanner has to repeatedly generate identical volume images of a target at the same coordinates. We tested the positioning accuracy of the prototype of an advanced workplace for image-guided surgery (AWIGS) which features an operating table capable of direct patient transfer into a CT scanner. Volume images (N = 154) of a specialized phantom were analysed for translational shifting after various table translations. Variables included added weight and phantom position on the table. The navigation system's calibration accuracy was determined (bias 2.1 mm, precision ± 0.7 mm, N = 12). In repeated use, a bias of 3.0 mm and a precision of ± 0.9 mm (N = 10) were maintainable. Instances of translational image shifting were related to the table-to-CT scanner docking mechanism. A distance scaling error when altering the table's height was detected. Initial prototype problems visible in our study causing systematic errors were resolved by repeated system calibrations between interventions. We conclude that the accuracy achieved is sufficient for a wide range of clinical applications in surgery and interventional radiology.

Modified Navigation Instructions for Spatial Navigation Assistance Systems Lead to Incidental Spatial Learning

PubMed Central

Gramann, Klaus; Hoepner, Paul; Karrer-Gauss, Katja

2017-01-01

Spatial cognitive skills deteriorate with the increasing use of automated GPS navigation and a general decrease in the ability to orient in space might have further impact on independence, autonomy, and quality of life. In the present study we investigate whether modified navigation instructions support incidental spatial knowledge acquisition. A virtual driving environment was used to examine the impact of modified navigation instructions on spatial learning while using a GPS navigation assistance system. Participants navigated through a simulated urban and suburban environment, using navigation support to reach their destination. Driving performance as well as spatial learning was thereby assessed. Three navigation instruction conditions were tested: (i) a control group that was provided with classical navigation instructions at decision points, and two other groups that received navigation instructions at decision points including either (ii) additional irrelevant information about landmarks or (iii) additional personally relevant information (i.e., individual preferences regarding food, hobbies, etc.), associated with landmarks. Driving performance revealed no differences between navigation instructions. Significant improvements were observed in both modified navigation instruction conditions on three different measures of spatial learning and memory: subsequent navigation of the initial route without navigation assistance, landmark recognition, and sketch map drawing. Future navigation assistance systems could incorporate modified instructions to promote incidental spatial learning and to foster more general spatial cognitive abilities. Such systems might extend mobility across the lifespan. PMID:28243219

Investigation of new techniques for aircraft navigation using the omega navigation

NASA Technical Reports Server (NTRS)

Baxa, E. G., Jr.

1978-01-01

An OMEGA navigation receiver with a microprocessor as the computational component was investigated. A version of the INTEL 4004 microprocessor macroassembler suitable for use on the CDC-6600 system and development of a FORTRAN IV simulator program for the microprocessor was developed. Supporting studies included development and evaluation of navigation algorithms to generate relative position information from OMEGA VLF phase measurements. Simulation studies were used to evaluate assumptions made in developing a navigation equation in OMEGA Line of Position (LOP) coordinates. Included in the navigation algorithms was a procedure for calculating a position in latitude/longitude given an OMEGA LOP fix. Implementation of a digital phase locked loop (DPLL) was evaluated on the basic of phase response characteristics over a range of input phase variations. Included also is an analytical evaluation on the basis of error probability of an algorithm for automatic time synchronization of the receiver to the OMEGA broadcast format. The use of actual OMEGA phase data and published propagation prediction corrections to determine phase velocity estimates was discussed.

COBALT: Development of a Platform to Flight Test Lander GN&C Technologies on Suborbital Rockets

NASA Technical Reports Server (NTRS)

Carson, John M., III; Seubert, Carl R.; Amzajerdian, Farzin; Bergh, Chuck; Kourchians, Ara; Restrepo, Carolina I.; Villapando, Carlos Y.; O'Neal, Travis V.; Robertson, Edward A.; Pierrottet, Diego;

Mission Operations and Navigation Toolkit Environment

NASA Technical Reports Server (NTRS)

Sunseri, Richard F.; Wu, Hsi-Cheng; Hanna, Robert A.; Mossey, Michael P.; Duncan, Courtney B.; Evans, Scott E.; Evans, James R.; Drain, Theodore R.; Guevara, Michelle M.; Martin Mur, Tomas J.;

A navigation system for the visually impaired an intelligent white cane.

PubMed

Fukasawa, A Jin; Magatani, Kazusihge

2012-01-01

In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. Our developed instrument consists of a navigation system and a map information system. These systems are installed on a white cane. Our navigation system can follow a colored navigation line that is set on the floor. In this system, a color sensor installed on the tip of a white cane, this sensor senses a color of navigation line and the system informs the visually impaired that he/she is walking along the navigation line by vibration. This color recognition system is controlled by a one-chip microprocessor. RFID tags and a receiver for these tags are used in the map information system. RFID tags are set on the colored navigation line. An antenna for RFID tags and a tag receiver are also installed on a white cane. The receiver receives the area information as a tag-number and notifies map information to the user by mp3 formatted pre-recorded voice. And now, we developed the direction identification technique. Using this technique, we can detect a user's walking direction. A triaxiality acceleration sensor is used in this system. Three normal subjects who were blindfolded with an eye mask were tested with our developed navigation system. All of them were able to walk along the navigation line perfectly. We think that the performance of the system is good. Therefore, our system will be extremely valuable in supporting the activities of the visually impaired.

A novel platform for electromagnetic navigated ultrasound bronchoscopy (EBUS).

PubMed

Sorger, Hanne; Hofstad, Erlend Fagertun; Amundsen, Tore; Langø, Thomas; Leira, Håkon Olav

2016-08-01

Endobronchial ultrasound transbronchial needle aspiration (EBUS-TBNA) of mediastinal lymph nodes is essential for lung cancer staging and distinction between curative and palliative treatment. Precise sampling is crucial. Navigation and multimodal imaging may improve the efficiency of EBUS-TBNA. We demonstrate a novel EBUS-TBNA navigation system in a dedicated airway phantom. Using a convex probe EBUS bronchoscope (CP-EBUS) with an integrated sensor for electromagnetic (EM) position tracking, we performed navigated CP-EBUS in a phantom. Preoperative computed tomography (CT) and real-time ultrasound (US) images were integrated into a navigation platform for EM navigated bronchoscopy. The coordinates of targets in CT and US volumes were registered in the navigation system, and the position deviation was calculated. The system visualized all tumor models and displayed their fused CT and US images in correct positions in the navigation system. Navigating the EBUS bronchoscope was fast and easy. Mean error observed between US and CT positions for 11 target lesions (37 measurements) was [Formula: see text] mm, maximum error was 5.9 mm. The feasibility of our novel navigated CP-EBUS system was successfully demonstrated. An EBUS navigation system is needed to meet future requirements of precise mediastinal lymph node mapping, and provides new opportunities for procedure documentation in EBUS-TBNA.

Regionalized Lunar South Pole Surface Navigation System Analysis

NASA Technical Reports Server (NTRS)

Welch, Bryan W.

2008-01-01

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.

Sensitivity analysis of helicopter IMC decelerating steep approach and landing performance to navigation system parameters

NASA Technical Reports Server (NTRS)

Karmali, M. S.; Phatak, A. V.

1982-01-01

Results of a study to investigate, by means of a computer simulation, the performance sensitivity of helicopter IMC DSAL operations as a function of navigation system parameters are presented. A mathematical model representing generically a navigation system is formulated. The scenario simulated consists of a straight in helicopter approach to landing along a 6 deg glideslope. The deceleration magnitude chosen is 03g. The navigation model parameters are varied and the statistics of the total system errors (TSE) computed. These statistics are used to determine the critical navigation system parameters that affect the performance of the closed-loop navigation, guidance and control system of a UH-1H helicopter.

Precision Landing and Hazard Avoidance Doman

NASA Technical Reports Server (NTRS)

Robertson, Edward A.; Carson, John M., III

2016-01-01

The Precision Landing and Hazard Avoidance (PL&HA) domain addresses the development, integration, testing, and spaceflight infusion of sensing, processing, and GN&C functions critical to the success and safety of future human and robotic exploration missions. PL&HA sensors also have applications to other mission events, such as rendezvous and docking. Autonomous PL&HA builds upon the core GN&C capabilities developed to enable soft, controlled landings on the Moon, Mars, and other solar system bodies. Through the addition of a Terrain Relative Navigation (TRN) function, precision landing within tens of meters of a map-based target is possible. The addition of a 3-D terrain mapping lidar sensor improves the probability of a safe landing via autonomous, real-time Hazard Detection and Avoidance (HDA). PL&HA significantly improves the probability of mission success and enhances access to sites of scientific interest located in challenging terrain. PL&HA can also utilize external navigation aids, such as navigation satellites and surface beacons. Advanced Lidar Sensors High precision ranging, velocimetry, and 3-D terrain mapping Terrain Relative Navigation (TRN) TRN compares onboard reconnaissance data with real-time terrain imaging data to update the S/C position estimate Hazard Detection and Avoidance (HDA) Generates a high-resolution, 3-D terrain map in real-time during the approach trajectory to identify safe landing targets Inertial Navigation During Terminal Descent High precision surface relative sensors enable accurate inertial navigation during terminal descent and a tightly controlled touchdown within meters of the selected safe landing target.

33 CFR 127.1109 - Lighting systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Lighting systems. 127.1109 Section 127.1109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Design and Construction § 127.1109 Lighting systems...

33 CFR 127.1109 - Lighting systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Lighting systems. 127.1109 Section 127.1109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Design and Construction § 127.1109 Lighting systems...

33 CFR 127.1109 - Lighting systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Lighting systems. 127.1109 Section 127.1109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Design and Construction § 127.1109 Lighting systems...

33 CFR 127.1109 - Lighting systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Lighting systems. 127.1109 Section 127.1109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Design and Construction § 127.1109 Lighting systems...

33 CFR 127.1109 - Lighting systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Lighting systems. 127.1109 Section 127.1109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Hazardous Gas Design and Construction § 127.1109 Lighting systems...

Needle and catheter navigation using electromagnetic tracking for computer-assisted C-arm CT interventions

NASA Astrophysics Data System (ADS)

Nagel, Markus; Hoheisel, Martin; Petzold, Ralf; Kalender, Willi A.; Krause, Ulrich H. W.

2007-03-01

Integrated solutions for navigation systems with CT, MR or US systems become more and more popular for medical products. Such solutions improve the medical workflow, reduce hardware, space and costs requirements. The purpose of our project was to develop a new electromagnetic navigation system for interventional radiology which is integrated into C-arm CT systems. The application is focused on minimally invasive percutaneous interventions performed under local anaesthesia. Together with a vacuum-based patient immobilization device and newly developed navigation tools (needles, panels) we developed a safe and fully automatic navigation system. The radiologist can directly start with navigated interventions after loading images without any prior user interaction. The complete system is adapted to the requirements of the radiologist and to the clinical workflow. For evaluation of the navigation system we performed different phantom studies and achieved an average accuracy of better than 2.0 mm.

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

DOT National Transportation Integrated Search

2001-02-19

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

Geo-navigation system for rotary percussion drilling in rocks of high and low electrical conductivity

NASA Astrophysics Data System (ADS)

Konurin, AI; Khmelinin, AP; Denisova, EV

2018-03-01

The currently available drill navigation systems, with their benefits and shortcomings are reviewed. A mathematical model is built to describe the inertial navigation system movement in horizontal and inclined drilling. A prototype model of the inertial navigation system for rotary percussion drills has been designed.

Preliminary navigation accuracy analysis for the TDRSS Onboard Navigation System (TONS) experiment on EP/EUVE

NASA Technical Reports Server (NTRS)

Gramling, C. J.; Long, A. C.; Lee, T.; Ottenstein, N. A.; Samii, M. V.

1991-01-01

A Tracking and Data Relay Satellite System (TDRSS) Onboard Navigation System (TONS) is currently being developed by NASA to provide a high accuracy autonomous navigation capability for users of TDRSS and its successor, the Advanced TDRSS (ATDRSS). The fully autonomous user onboard navigation system will support orbit determination, time determination, and frequency determination, based on observation of a continuously available, unscheduled navigation beacon signal. A TONS experiment will be performed in conjunction with the Explorer Platform (EP) Extreme Ultraviolet Explorer (EUVE) mission to flight quality TONS Block 1. An overview is presented of TONS and a preliminary analysis of the navigation accuracy anticipated for the TONS experiment. Descriptions of the TONS experiment and the associated navigation objectives, as well as a description of the onboard navigation algorithms, are provided. The accuracy of the selected algorithms is evaluated based on the processing of realistic simulated TDRSS one way forward link Doppler measurements. The analysis process is discussed and the associated navigation accuracy results are presented.

Celestial Navigation in the 21st Century

NASA Astrophysics Data System (ADS)

Kaplan, George H.

2014-05-01

Despite the ubiquity of GPS receivers in modern life for both timekeeping and geolocation, other forms of navigation remain important because of the weakness of the GPS signals (and those from similar sat-nav systems) and the ease with which they can be jammed. GPS jammers are available for sale on the Internet. The defense and civil aviation communities are particularly concerned about “GPS denial”, whether intentional or accidental, during critical operations.Automated star trackers for navigation have been available since the 1950s. Modern compact observing systems, operating in the far-red and near-IR bands, can detect useful numbers of stars even in the daytime at sea level. A capability to measure the directions of stars relative to some local set of coordinate axes is advantageous for many types of vehicles, whether on the ground, at sea, in the air, or in space, because it provides a direct connection to the inertial reference system represented by current star catalogs. Such a capability can yield precise absolute orientation information not available in any other way. Automated celestial observing systems can be effectively coupled to inertial navigation systems (INS), providing “truth” data for constraining the drift in the INS navigation solution, even if stellar observations are not continuously available due to weather. However, obtaining precise latitude and longitude from stellar observations alone, on a moving platform, remains a challenge, because it requires a determination of the direction to the center of the Earth, i.e., the gravity vertical. General relativity tells us that on-board (“lab”) measurements cannot separate the acceleration of gravity from the acceleration of the platform. Various schemes for overcoming this fundamental problem have been used in the past, at low accuracy, and better ones have been proposed for modern applications. This paper will review some recent developments in this rapidly advancing field.

Lunar far side surface navigation using Linked Autonomous Interplanetary Satellite Orbit Navigation (LiAISON)

NASA Astrophysics Data System (ADS)

Hesar, Siamak G.; Parker, Jeffrey S.; Leonard, Jason M.; McGranaghan, Ryan M.; Born, George H.

2015-12-01

We study the application of Linked Autonomous Interplanetary Satellite Orbit Navigation (LiAISON) to track vehicles on the far side of the lunar surface. The LiAISON architecture is demonstrated to achieve accurate orbit determination solutions for various mission scenarios in the Earth-Moon system. Given the proper description of the force field, LiAISON is capable of producing absolute orbit determination solutions using relative satellite-to-satellite tracking observations alone. The lack of direct communication between Earth-based tracking stations and the far side of the Moon provides an ideal opportunity for implementing LiAISON. This paper presents a novel approach to use the LiAISON architecture to perform autonomous navigation of assets on the lunar far side surface. Relative measurements between a spacecraft placed in an EML-2 halo orbit and lunar surface asset(s) are simulated and processed. Comprehensive simulation results show that absolute states of the surface assets are observable with an achieved accuracy of the position estimate on the order of tens of meters.

Comparison of Precision between Optical and Electromagnetic Navigation Systems in Total Knee Arthroplasty

PubMed Central

Rhee, Seung Joon; Park, Shi Hwan; Cho, He Myung

2014-01-01

Purpose The purpose of this study is to compare and analyze the precision of optical and electromagnetic navigation systems in total knee arthroplasty (TKA). Materials and Methods We retrospectively reviewed 60 patients who underwent TKA using an optical navigation system and 60 patients who underwent TKA using an electromagnetic navigation system from June 2010 to March 2012. The mechanical axis that was measured on preoperative radiographs and by the intraoperative navigation systems were compared between the groups. The postoperative positions of the femoral and tibial components in the sagittal and coronal plane were assessed. Results The difference of the mechanical axis measured on the preoperative radiograph and by the intraoperative navigation systems was 0.6 degrees more varus in the electromagnetic navigation system group than in the optical navigation system group, but showed no statistically significant difference between the two groups (p>0.05). The positions of the femoral and tibial components in the sagittal and coronal planes on the postoperative radiographs also showed no statistically significant difference between the two groups (p>0.05). Conclusions In TKA, both optical and electromagnetic navigation systems showed high accuracy and reproducibility, and the measurements from the postoperative radiographs showed no significant difference between the two groups. PMID:25505703

Evaluating the cost-effectiveness of cancer patient navigation programs: conceptual and practical issues.

PubMed

Ramsey, Scott; Whitley, Elizabeth; Mears, Victoria Warren; McKoy, June M; Everhart, Rachel M; Caswell, Robert J; Fiscella, Kevin; Hurd, Thelma C; Battaglia, Tracy; Mandelblatt, Jeanne

2009-12-01

Patient navigators-individuals who assist patients through the healthcare system to improve access to and understanding of their health and healthcare-are increasingly used for underserved individuals at risk for or with cancer. Navigation programs can improve access, but it is unclear whether they improve the efficiency and efficacy of cancer diagnostic and therapeutic services at a reasonable cost, such that they would be considered cost-effective. In the current study, the authors outline a conceptual model for evaluating the cost-effectiveness of cancer navigation programs. They describe how this model is being applied to the Patient Navigation Research Program, a multicenter study supported by the National Cancer Institute's Center to Reduce Cancer Health Disparities. The Patient Navigation Research Program is testing navigation interventions that aim to reduce time to delivery of quality cancer care (noncancer resolution or cancer diagnosis and treatment) after identification of a screening abnormality. Examples of challenges to evaluating cost-effectiveness of navigation programs include the heterogeneity of navigation programs, the sometimes distant relation between navigation programs and outcome of interest (eg, improving access to prompt diagnostic resolution and life-years gained), and accounting for factors in underserved populations that may influence both access to services and outcomes. In this article, the authors discuss several strategies for addressing these barriers. Evaluating the costs and impact of navigation will require some novel methods, but will be critical in recommendations concerning dissemination of navigation programs. (c) 2009 American Cancer Society.

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

NASA Technical Reports Server (NTRS)

Truong, Son H.

1999-01-01

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

Interface methods for using intranet portal organizational memory information system.

PubMed

Ji, Yong Gu; Salvendy, Gavriel

2004-12-01

In this paper, an intranet portal is considered as an information infrastructure (organizational memory information system, OMIS) supporting organizational learning. The properties and the hierarchical structure of information and knowledge in an intranet portal OMIS was identified as a problem for navigation tools of an intranet portal interface. The problem relates to navigation and retrieval functions of intranet portal OMIS and is expected to adversely affect user performance, satisfaction, and usefulness. To solve the problem, a conceptual model for navigation tools of an intranet portal interface was proposed and an experiment using a crossover design was conducted with 10 participants. In the experiment, a separate access method (tabbed tree tool) was compared to an unified access method (single tree tool). The results indicate that each information/knowledge repository for which a user has a different structural knowledge should be handled separately with a separate access to increase user satisfaction and the usefulness of the OMIS and to improve user performance in navigation.

33 CFR 127.705 - Security systems.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security systems. 127.705 Section 127.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Natural Gas Security § 127.705 Security systems. The operator shall...

33 CFR 127.705 - Security systems.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security systems. 127.705 Section 127.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Natural Gas Security § 127.705 Security systems. The operator shall...

33 CFR 127.705 - Security systems.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security systems. 127.705 Section 127.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Natural Gas Security § 127.705 Security systems. The operator shall...

33 CFR 127.705 - Security systems.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security systems. 127.705 Section 127.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Natural Gas Security § 127.705 Security systems. The operator shall...

33 CFR 127.705 - Security systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security systems. 127.705 Section 127.705 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... Waterfront Facilities Handling Liquefied Natural Gas Security § 127.705 Security systems. The operator shall...

Satellite Navigation Systems: Policy, Commercial and Technical Interaction.

NASA Astrophysics Data System (ADS)

Rycroft, M.

2003-12-01

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

Improving the Accuracy of Direct Geo-referencing of Smartphone-Based Mobile Mapping Systems Using Relative Orientation and Scene Geometric Constraints.

PubMed

Alsubaie, Naif M; Youssef, Ahmed A; El-Sheimy, Naser

2017-09-30

This paper introduces a new method which facilitate the use of smartphones as a handheld low-cost mobile mapping system (MMS). Smartphones are becoming more sophisticated and smarter and are quickly closing the gap between computers and portable tablet devices. The current generation of smartphones are equipped with low-cost GPS receivers, high-resolution digital cameras, and micro-electro mechanical systems (MEMS)-based navigation sensors (e.g., accelerometers, gyroscopes, magnetic compasses, and barometers). These sensors are in fact the essential components for a MMS. However, smartphone navigation sensors suffer from the poor accuracy of global navigation satellite System (GNSS), accumulated drift, and high signal noise. These issues affect the accuracy of the initial Exterior Orientation Parameters (EOPs) that are inputted into the bundle adjustment algorithm, which then produces inaccurate 3D mapping solutions. This paper proposes new methodologies for increasing the accuracy of direct geo-referencing of smartphones using relative orientation and smartphone motion sensor measurements as well as integrating geometric scene constraints into free network bundle adjustment. The new methodologies incorporate fusing the relative orientations of the captured images and their corresponding motion sensor measurements to improve the initial EOPs. Then, the geometric features (e.g., horizontal and vertical linear lines) visible in each image are extracted and used as constraints in the bundle adjustment procedure which correct the relative position and orientation of the 3D mapping solution.

Improving the Accuracy of Direct Geo-referencing of Smartphone-Based Mobile Mapping Systems Using Relative Orientation and Scene Geometric Constraints

PubMed Central

Alsubaie, Naif M.; Youssef, Ahmed A.; El-Sheimy, Naser

2017-01-01

This paper introduces a new method which facilitate the use of smartphones as a handheld low-cost mobile mapping system (MMS). Smartphones are becoming more sophisticated and smarter and are quickly closing the gap between computers and portable tablet devices. The current generation of smartphones are equipped with low-cost GPS receivers, high-resolution digital cameras, and micro-electro mechanical systems (MEMS)-based navigation sensors (e.g., accelerometers, gyroscopes, magnetic compasses, and barometers). These sensors are in fact the essential components for a MMS. However, smartphone navigation sensors suffer from the poor accuracy of global navigation satellite System (GNSS), accumulated drift, and high signal noise. These issues affect the accuracy of the initial Exterior Orientation Parameters (EOPs) that are inputted into the bundle adjustment algorithm, which then produces inaccurate 3D mapping solutions. This paper proposes new methodologies for increasing the accuracy of direct geo-referencing of smartphones using relative orientation and smartphone motion sensor measurements as well as integrating geometric scene constraints into free network bundle adjustment. The new methodologies incorporate fusing the relative orientations of the captured images and their corresponding motion sensor measurements to improve the initial EOPs. Then, the geometric features (e.g., horizontal and vertical linear lines) visible in each image are extracted and used as constraints in the bundle adjustment procedure which correct the relative position and orientation of the 3D mapping solution. PMID:28973958

Canoe: An Autonomous Infrastructure-Free Indoor Navigation System.

PubMed

Dong, Kai; Wu, Wenjia; Ye, Haibo; Yang, Ming; Ling, Zhen; Yu, Wei

2017-04-30

The development of the Internet of Things (IoT) has accelerated research in indoor navigation systems, a majority of which rely on adequate wireless signals and sources. Nonetheless, deploying such a system requires periodic site-survey, which is time consuming and labor intensive. To address this issue, in this paper we present Canoe , an indoor navigation system that considers shopping mall scenarios. In our system, we do not assume any prior knowledge, such as floor-plan or the shop locations, access point placement or power settings, historical RSS measurements or fingerprints, etc. Instead, Canoe requires only that the shop owners collect and publish RSS values at the entrances of their shops and can direct a consumer to any of these shops by comparing the observed RSS values. The locations of the consumers and the shops are estimated using maximum likelihood estimation. In doing this, the direction of the target shop relative to the current orientation of the consumer can be precisely computed, such that the direction that a consumer should move can be determined. We have conducted extensive simulations using a real-world dataset. Our experiments in a real shopping mall demonstrate that if 50% of the shops publish their RSS values, Canoe can precisely navigate a consumer within 30 s, with an error rate below 9%.

Canoe: An Autonomous Infrastructure-Free Indoor Navigation System

PubMed Central

Dong, Kai; Wu, Wenjia; Ye, Haibo; Yang, Ming; Ling, Zhen; Yu, Wei

2017-01-01

The development of the Internet of Things (IoT) has accelerated research in indoor navigation systems, a majority of which rely on adequate wireless signals and sources. Nonetheless, deploying such a system requires periodic site-survey, which is time consuming and labor intensive. To address this issue, in this paper we present Canoe, an indoor navigation system that considers shopping mall scenarios. In our system, we do not assume any prior knowledge, such as floor-plan or the shop locations, access point placement or power settings, historical RSS measurements or fingerprints, etc. Instead, Canoe requires only that the shop owners collect and publish RSS values at the entrances of their shops and can direct a consumer to any of these shops by comparing the observed RSS values. The locations of the consumers and the shops are estimated using maximum likelihood estimation. In doing this, the direction of the target shop relative to the current orientation of the consumer can be precisely computed, such that the direction that a consumer should move can be determined. We have conducted extensive simulations using a real-world dataset. Our experiments in a real shopping mall demonstrate that if 50% of the shops publish their RSS values, Canoe can precisely navigate a consumer within 30 s, with an error rate below 9%. PMID:28468291

Time and frequency applications.

PubMed

Hellwig, H

1993-01-01

An overview is given of the capabilities of atomic clocks and quartz crystal oscillators in terms of available precision of time and frequency signals. The generation, comparison, and dissemination of time and frequency is then discussed. The principal focus is to survey uses of time and frequency in navigation, communication, and science. The examples given include the Global Positioning System, a satellite-based global navigation system, and general and dedicated communication networks, as well as experiments in general relativity and radioastronomy. The number of atomic clocks and crystal oscillators that are in actual use worldwide is estimated.

Three-dimensional mapping in the electrophysiological laboratory.

PubMed

Maury, Philippe; Monteil, Benjamin; Marty, Lilian; Duparc, Alexandre; Mondoly, Pierre; Rollin, Anne

2018-06-07

Investigation and catheter ablation of cardiac arrhythmias are currently still based on optimal knowledge of arrhythmia mechanisms in relation to the cardiac anatomy involved, in order to target their crucial components. Currently, most complex arrhythmias are investigated using three-dimensional electroanatomical navigation systems, because these are felt to optimally integrate both the anatomical and electrophysiological features of a given arrhythmia in a given patient. In this article, we review the technical background of available three-dimensional electroanatomical navigation systems, and their potential use in complex ablations. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Robotics in invasive cardiac electrophysiology.

PubMed

Shurrab, Mohammed; Schilling, Richard; Gang, Eli; Khan, Ejaz M; Crystal, Eugene

2014-07-01

Robotic systems allow for mapping and ablation of different arrhythmia substrates replacing hand maneuvering of intracardiac catheters with machine steering. Currently there are four commercially available robotic systems. Niobe magnetic navigation system (Stereotaxis Inc., St Louis, MO) and Sensei robotic navigation system (Hansen Medical Inc., Mountain View, CA) have an established platform with at least 10 years of clinical studies looking at their efficacy and safety. AMIGO Remote Catheter System (Catheter Robotics, Inc., Mount Olive, NJ) and Catheter Guidance Control and Imaging (Magnetecs, Inglewood, CA) are in the earlier phases of implementations with ongoing feasibility and some limited clinical studies. This review discusses the advantages and limitations related to each existing system and highlights the ideal futuristic robotic system that may include the most promising features of the current ones.

Performance Analysis on Carrier Phase-Based Tightly-Coupled GPS/BDS/INS Integration in GNSS Degraded and Denied Environments

PubMed Central

Han, Houzeng; Wang, Jian; Wang, Jinling; Tan, Xinglong

2015-01-01

The integration of Global Navigation Satellite Systems (GNSS) carrier phases with Inertial Navigation System (INS) measurements is essential to provide accurate and continuous position, velocity and attitude information, however it is necessary to fix ambiguities rapidly and reliably to obtain high accuracy navigation solutions. In this paper, we present the notion of combining the Global Positioning System (GPS), the BeiDou Navigation Satellite System (BDS) and low-cost micro-electro-mechanical sensors (MEMS) inertial systems for reliable navigation. An adaptive multipath factor-based tightly-coupled (TC) GPS/BDS/INS integration algorithm is presented and the overall performance of the integrated system is illustrated. A twenty seven states TC GPS/BDS/INS model is adopted with an extended Kalman filter (EKF), which is carried out by directly fusing ambiguity fixed double-difference (DD) carrier phase measurements with the INS predicted pseudoranges to estimate the error states. The INS-aided integer ambiguity resolution (AR) strategy is developed by using a dynamic model, a two-step estimation procedure is applied with adaptively estimated covariance matrix to further improve the AR performance. A field vehicular test was carried out to demonstrate the positioning performance of the combined system. The results show the TC GPS/BDS/INS system significantly improves the single-epoch AR reliability as compared to that of GPS/BDS-only or single satellite navigation system integrated strategy, especially for high cut-off elevations. The AR performance is also significantly improved for the combined system with adaptive covariance matrix in the presence of low elevation multipath related to the GNSS-only case. A total of fifteen simulated outage tests also show that the time to relock of the GPS/BDS signals is shortened, which improves the system availability. The results also indicate that TC integration system achieves a few centimeters accuracy in positioning based on the comparison analysis and covariance analysis, even in harsh environments (e.g., in urban canyons), thus we can see the advantage of positioning at high cut-off elevations that the combined GPS/BDS brings. PMID:25875191

Performance analysis on carrier phase-based tightly-coupled GPS/BDS/INS integration in GNSS degraded and denied environments.

PubMed

Han, Houzeng; Wang, Jian; Wang, Jinling; Tan, Xinglong

2015-04-14

The integration of Global Navigation Satellite Systems (GNSS) carrier phases with Inertial Navigation System (INS) measurements is essential to provide accurate and continuous position, velocity and attitude information, however it is necessary to fix ambiguities rapidly and reliably to obtain high accuracy navigation solutions. In this paper, we present the notion of combining the Global Positioning System (GPS), the BeiDou Navigation Satellite System (BDS) and low-cost micro-electro-mechanical sensors (MEMS) inertial systems for reliable navigation. An adaptive multipath factor-based tightly-coupled (TC) GPS/BDS/INS integration algorithm is presented and the overall performance of the integrated system is illustrated. A twenty seven states TC GPS/BDS/INS model is adopted with an extended Kalman filter (EKF), which is carried out by directly fusing ambiguity fixed double-difference (DD) carrier phase measurements with the INS predicted pseudoranges to estimate the error states. The INS-aided integer ambiguity resolution (AR) strategy is developed by using a dynamic model, a two-step estimation procedure is applied with adaptively estimated covariance matrix to further improve the AR performance. A field vehicular test was carried out to demonstrate the positioning performance of the combined system. The results show the TC GPS/BDS/INS system significantly improves the single-epoch AR reliability as compared to that of GPS/BDS-only or single satellite navigation system integrated strategy, especially for high cut-off elevations. The AR performance is also significantly improved for the combined system with adaptive covariance matrix in the presence of low elevation multipath related to the GNSS-only case. A total of fifteen simulated outage tests also show that the time to relock of the GPS/BDS signals is shortened, which improves the system availability. The results also indicate that TC integration system achieves a few centimeters accuracy in positioning based on the comparison analysis and covariance analysis, even in harsh environments (e.g., in urban canyons), thus we can see the advantage of positioning at high cut-off elevations that the combined GPS/BDS brings.

Do Better-rated Navigators Improve Patient Satisfaction with Cancer-Related Care?

PubMed Central

Jean-Pierre, Pascal; Winters, Paul C.; Clark, Jack A.; Warren-Mears, Victoria; Wells, Kristen J.; Post, Douglas M.; LaVerda, Nancy; Van Duyn, Mary Ann; Fiscella, Kevin

2013-01-01

Background Patient navigation has emerged as a promising strategy for addressing racial-ethnic and socioeconomic disparities in cancer-related care. However, little is known about the impact of patients’ perception of the quality of navigation on patient outcomes. We examined the impact of better-rated navigators on patients’ satisfaction with cancer related care. Methods The sample included 1,593 adults (85.8% with abnormal cancer screening and 14.2% with confirmed cancer diagnosis) who received patient navigation. We defined better-rated navigators as those scoring above the first quartile of mean scores on the Patient Satisfaction with Interpersonal Relationship with Navigator (PSN-I) scale. We defined patient satisfaction based on scores above or below the median of the Patient Satisfaction with Cancer-Related Care scale (PSCC). We controlled for patient and site characteristics using backward selection logistic regression analyses. Results Among patients with abnormal screening, having a better-rated navigator was associated with higher score on the PSCC (p<0.05). After controlling for other bivariate predictors of satisfaction (e.g., age, race, income, and household size), navigation by better-rated navigators was associated with a greater likelihood of having higher patient satisfaction (Odds Ratio [OR]: 1.38, 95% Confidence Interval [CI]: 1.05-1.82). Similar findings between better-rated navigators and score on the PSCC were found for participants with diagnosed cancer (OR: 3.06, 95% CI: 1.56-6.0). Conclusions Patients navigated by better-rated navigators reported higher satisfaction with their cancer-related care. PMID:23807598

Technology scan of future traveler information systems and applications in Georgia.

DOT National Transportation Integrated Search

2013-10-01

Statewide traveler information provided in Georgia through its NaviGAtor/5-1-1 system is : primarily based on Intelligent Transportation Systems (ITS) related to freeway traffic : management. The purpose of this study is to evaluate traveler informat...

46 CFR 112.43-7 - Navigating bridge distribution panel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Navigating bridge distribution panel. 112.43-7 Section... EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-7 Navigating bridge distribution... supplied from a distribution panel on the navigating bridge: (1) Navigation lights not supplied by the...

33 CFR 62.63 - Recommendations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Recommendations. 62.63 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.63 Recommendations. (a) The public may recommend changes to existing aids to navigation, request new aids or the...

46 CFR 112.43-7 - Navigating bridge distribution panel.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Navigating bridge distribution panel. 112.43-7 Section... EMERGENCY LIGHTING AND POWER SYSTEMS Emergency Lighting Systems § 112.43-7 Navigating bridge distribution... supplied from a distribution panel on the navigating bridge: (1) Navigation lights not supplied by the...

6DOF Testing of the SLS Inertial Navigation Unit

NASA Technical Reports Server (NTRS)

Geohagan, Kevin; Bernard, Bill; Oliver, T. Emerson; Leggett, Jared; Strickland, Dennis

2018-01-01

The Navigation System on the NASA Space Launch System (SLS) Block 1 vehicle performs initial alignment of the Inertial Navigation System (INS) navigation frame through gyrocompass alignment (GCA). Because the navigation architecture for the SLS Block 1 vehicle is a purely inertial system, the accuracy of the achieved orbit relative to mission requirements is very sensitive to initial alignment accuracy. The assessment of this sensitivity and many others via simulation is a part of the SLS Model-Based Design and Model-Based Requirements approach. As a part of the aforementioned, 6DOF Monte Carlo simulation is used in large part to develop and demonstrate verification of program requirements. To facilitate this and the GN&C flight software design process, an SLS-Program-controlled Design Math Model (DMM) of the SLS INS was developed by the SLS Navigation Team. The SLS INS model implements all of the key functions of the hardware-namely, GCA, inertial navigation, and FDIR (Fault Detection, Isolation, and Recovery)-in support of SLS GN&C design requirements verification. Despite the strong sensitivity to initial alignment, GCA accuracy requirements were not verified by test due to program cost and schedule constraints. Instead, the system relies upon assessments performed using the SLS INS model. In order to verify SLS program requirements by analysis, the SLS INS model is verified and validated against flight hardware. In lieu of direct testing of GCA accuracy in support of requirement verification, the SLS Navigation Team proposed and conducted an engineering test to, among other things, validate the GCA performance and overall behavior of the SLS INS model through comparison with test data. This paper will detail dynamic hardware testing of the SLS INS, conducted by the SLS Navigation Team at Marshall Space Flight Center's 6DOF Table Facility, in support of GCA performance characterization and INS model validation. A 6-DOF motion platform was used to produce 6DOF pad twist and sway dynamics while a simulated SLS flight computer communicated with the INS. Tests conducted include an evaluation of GCA algorithm robustness to increasingly dynamic pad environments, an examination of GCA algorithm stability and accuracy over long durations, and a long-duration static test to gather enough data for Allan Variance analysis. Test setup, execution, and data analysis will be discussed, including analysis performed in support of SLS INS model validation.

Multiple Coaxial Catheter System for Reliable Access in Interventional Stroke Therapy

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

Kulcsar, Zsolt, E-mail: kulcsarzsolt22@gmail.com; Yilmaz, Hasan; Bonvin, Christophe

2010-12-15

In some patients with acute cerebral vessel occlusion, navigating mechanical thrombectomy systems is difficult due to tortuous anatomy of the aortic arch, carotid arteries, or vertebral arteries. Our purpose was to describe a multiple coaxial catheter system used for mechanical revascularization that helps navigation and manipulations in tortuous vessels. A triple or quadruple coaxial catheter system was built in 28 consecutive cases presenting with acute ischemic stroke. All cases were treated by mechanical thrombectomy with the Penumbra System. In cases of unsuccessful thrombo-aspiration, additional thrombolysis or angioplasty with stent placement was used for improving recanalization. The catheter system consisted ofmore » an outermost 8-Fr and an intermediate 6-Fr guiding catheter, containing the inner Penumbra reperfusion catheters. The largest, 4.1-Fr, reperfusion catheter was navigated over a Prowler Select Plus microcatheter. The catheter system provided access to reach the cerebral lesions and provided stability for the mechanically demanding manipulations of thromboaspiration and stent navigation in all cases. Apart from their mechanical role, the specific parts of the system could also provide access to different types of interventions, like carotid stenting through the 8-Fr guiding catheter and intracranial stenting and thrombolysis through the Prowler Select Plus microcatheter. In this series, there were no complications related to the catheter system. In conclusion, building up a triple or quadruple coaxial system proved to be safe and efficient in our experience for the mechanical thrombectomy treatment of acute ischemic stroke.« less

NFC Internal: An Indoor Navigation System

PubMed Central

Ozdenizci, Busra; Coskun, Vedat; Ok, Kerem

2015-01-01

Indoor navigation systems have recently become a popular research field due to the lack of GPS signals indoors. Several indoors navigation systems have already been proposed in order to eliminate deficiencies; however each of them has several technical and usability limitations. In this study, we propose NFC Internal, a Near Field Communication (NFC)-based indoor navigation system, which enables users to navigate through a building or a complex by enabling a simple location update, simply by touching NFC tags those are spread around and orient users to the destination. In this paper, we initially present the system requirements, give the design details and study the viability of NFC Internal with a prototype application and a case study. Moreover, we evaluate the performance of the system and compare it with existing indoor navigation systems. It is seen that NFC Internal has considerable advantages and significant contributions to existing indoor navigation systems in terms of security and privacy, cost, performance, robustness, complexity, user preference and commercial availability. PMID:25825976

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

NASA Technical Reports Server (NTRS)

Truong, S. H.

1999-01-01

Most navigation systems currently operated by NASA are ground-based, and require extensive support to produce accurate results. Recently developed systems that use Kalman filter and GPS 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.

Navigation concepts for MR image-guided interventions.

PubMed

Moche, Michael; Trampel, Robert; Kahn, Thomas; Busse, Harald

2008-02-01

The ongoing development of powerful magnetic resonance imaging techniques also allows for advanced possibilities to guide and control minimally invasive interventions. Various navigation concepts have been described for practically all regions of the body. The specific advantages and limitations of these concepts largely depend on the magnet design of the MR scanner and the interventional environment. Open MR scanners involve minimal patient transfer, which improves the interventional workflow and reduces the need for coregistration, ie, the mapping of spatial coordinates between imaging and intervention position. Most diagnostic scanners, in contrast, do not allow the physician to guide his instrument inside the magnet and, consequently, the patient needs to be moved out of the bore. Although adequate coregistration and navigation concepts for closed-bore scanners are technically more challenging, many developments are driven by the well-known capabilities of high-field systems and their better economic value. Advanced concepts such as multimodal overlays, augmented reality displays, and robotic assistance devices are still in their infancy but might propel the use of intraoperative navigation. The goal of this work is to give an update on MRI-based navigation and related techniques and to briefly discuss the clinical experience and limitations of some selected systems. (Copyright) 2008 Wiley-Liss, Inc.

Development of Navigation Doppler Lidar for Future Landing Mission

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Pierrottet, Diego F.; Carson, John M., III

2016-01-01

A coherent Navigation Doppler Lidar (NDL) sensor has been developed under the Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project to support future NASA missions to planetary bodies. This lidar sensor provides accurate surface-relative altitude and vector velocity data during the descent phase that can be used by an autonomous Guidance, Navigation, and Control (GN&C) system to precisely navigate the vehicle from a few kilometers above the ground to a designated location and execute a controlled soft touchdown. The operation and performance of the NDL was demonstrated through closed-loop flights onboard the rocket-propelled Morpheus vehicle in 2014. In Morpheus flights, conducted at the NASA Kennedy Space Center, the NDL data was used by an autonomous GN&C system to navigate and land the vehicle precisely at the selected location surrounded by hazardous rocks and craters. Since then, development efforts for the NDL have shifted toward enhancing performance, optimizing design, and addressing spaceflight size and mass constraints and environmental and reliability requirements. The next generation NDL, with expanded operational envelope and significantly reduced size, will be demonstrated in 2017 through a new flight test campaign onboard a commercial rocketpropelled test vehicle.

Visual orientation and navigation in nocturnal arthropods.

PubMed

Warrant, Eric; Dacke, Marie

2010-01-01

With their highly sensitive visual systems, the arthropods have evolved a remarkable capacity to orient and navigate at night. Whereas some navigate under the open sky, and take full advantage of the celestial cues available there, others navigate in more difficult conditions, such as through the dense understory of a tropical rainforest. Four major classes of orientation are performed by arthropods at night, some of which involve true navigation (i.e. travel to a distant goal that lies beyond the range of direct sensory contact): (1) simple straight-line orientation, typically for escape purposes; (2) nightly short-distance movements relative to a shoreline, typically in the context of feeding; (3) long-distance nocturnal migration at high altitude in the quest to locate favorable feeding or breeding sites, and (4) nocturnal excursions to and from a fixed nest or food site (i.e. homing), a task that in most species involves path integration and/or the learning and recollection of visual landmarks. These four classes of orientation--and their visual basis--are reviewed here, with special emphasis given to the best-understood animal systems that are representative of each. 2010 S. Karger AG, Basel.

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Automatic Identification System Shipborne Equipment-Prince William Sound. 164.43 Section 164.43 Navigation and Navigable Waters COAST GUARD... Automatic Identification System Shipborne Equipment—Prince William Sound. (a) Until December 31, 2004, each...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Automatic Identification System Shipborne Equipment-Prince William Sound. 164.43 Section 164.43 Navigation and Navigable Waters COAST GUARD... Automatic Identification System Shipborne Equipment—Prince William Sound. (a) Until December 31, 2004, each...

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Automatic Identification System Shipborne Equipment-Prince William Sound. 164.43 Section 164.43 Navigation and Navigable Waters COAST GUARD... Automatic Identification System Shipborne Equipment—Prince William Sound. (a) Until December 31, 2004, each...

Compensation of Horizontal Gravity Disturbances for High Precision Inertial Navigation

PubMed Central

Cao, Juliang; Wu, Meiping; Lian, Junxiang; Cai, Shaokun; Wang, Lin

2018-01-01

Horizontal gravity disturbances are an important factor that affects the accuracy of inertial navigation systems in long-duration ship navigation. In this paper, from the perspective of the coordinate system and vector calculation, the effects of horizontal gravity disturbance on the initial alignment and navigation calculation are simultaneously analyzed. Horizontal gravity disturbances cause the navigation coordinate frame built in initial alignment to not be consistent with the navigation coordinate frame in which the navigation calculation is implemented. The mismatching of coordinate frame violates the vector calculation law, which will have an adverse effect on the precision of the inertial navigation system. To address this issue, two compensation methods suitable for two different navigation coordinate frames are proposed, one of the methods implements the compensation in velocity calculation, and the other does the compensation in attitude calculation. Finally, simulations and ship navigation experiments confirm the effectiveness of the proposed methods. PMID:29562653

Age-Related Differences and Cognitive Correlates of Self-Reported and Direct Navigation Performance: The Effect of Real and Virtual Test Conditions Manipulation

PubMed Central

Taillade, Mathieu; N'Kaoua, Bernard; Sauzéon, Hélène

2016-01-01

The present study investigated the effect of aging on direct navigation measures and self-reported ones according to the real-virtual test manipulation. Navigation (wayfinding tasks) and spatial memory (paper-pencil tasks) performances, obtained either in real-world or in virtual-laboratory test conditions, were compared between young (n = 32) and older (n = 32) adults who had self-rated their everyday navigation behavior (SBSOD scale). Real age-related differences were observed in navigation tasks as well as in paper-pencil tasks, which investigated spatial learning relative to the distinction between survey-route knowledge. The manipulation of test conditions (real vs. virtual) did not change these age-related differences, which are mostly explained by age-related decline in both spatial abilities and executive functioning (measured with neuropsychological tests). In contrast, elderly adults did not differ from young adults in their self-reporting relative to everyday navigation, suggesting some underestimation of navigation difficulties by elderly adults. Also, spatial abilities in young participants had a mediating effect on the relations between actual and self-reported navigation performance, but not for older participants. So, it is assumed that the older adults carried out the navigation task with fewer available spatial abilities compared to young adults, resulting in inaccurate self-estimates. PMID:26834666

Age-Related Differences and Cognitive Correlates of Self-Reported and Direct Navigation Performance: The Effect of Real and Virtual Test Conditions Manipulation.

PubMed

Taillade, Mathieu; N'Kaoua, Bernard; Sauzéon, Hélène

2015-01-01

The present study investigated the effect of aging on direct navigation measures and self-reported ones according to the real-virtual test manipulation. Navigation (wayfinding tasks) and spatial memory (paper-pencil tasks) performances, obtained either in real-world or in virtual-laboratory test conditions, were compared between young (n = 32) and older (n = 32) adults who had self-rated their everyday navigation behavior (SBSOD scale). Real age-related differences were observed in navigation tasks as well as in paper-pencil tasks, which investigated spatial learning relative to the distinction between survey-route knowledge. The manipulation of test conditions (real vs. virtual) did not change these age-related differences, which are mostly explained by age-related decline in both spatial abilities and executive functioning (measured with neuropsychological tests). In contrast, elderly adults did not differ from young adults in their self-reporting relative to everyday navigation, suggesting some underestimation of navigation difficulties by elderly adults. Also, spatial abilities in young participants had a mediating effect on the relations between actual and self-reported navigation performance, but not for older participants. So, it is assumed that the older adults carried out the navigation task with fewer available spatial abilities compared to young adults, resulting in inaccurate self-estimates.

Tele-Operated Lunar Rover Navigation Using Lidar

NASA Technical Reports Server (NTRS)

Pedersen, Liam; Allan, Mark B.; Utz, Hans, Heinrich; Deans, Matthew C.; Bouyssounouse, Xavier; Choi, Yoonhyuk; Fluckiger, Lorenzo; Lee, Susan Y.; To, Vinh; Loh, Jonathan;

Gravity compensation in a Strapdown Inertial Navigation System to improve the attitude accuracy

NASA Astrophysics Data System (ADS)

Zhu, Jing; Wang, Jun; Wang, Xingshu; Yang, Shuai

2017-10-01

Attitude errors in a strapdown inertial navigation system due to gravity disturbances and system noises can be relatively large, although they are bound within the Schuler and the Earth rotation period. The principal objective of the investigation is to determine to what extent accurate gravity data can improve the attitude accuracy. The way the gravity disturbances affect the attitude were analyzed and compared with system noises by the analytic solution and simulation. The gravity disturbances affect the attitude accuracy by introducing the initial attitude error and the equivalent accelerometer bias. With the development of the high precision inertial devices and the application of the rotation modulation technology, the gravity disturbance cannot be neglected anymore. The gravity compensation was performed using the EGM2008 and simulations with and without accurate gravity compensation under varying navigation conditions were carried out. The results show that the gravity compensation improves the horizontal components of attitude accuracy evidently while the yaw angle is badly affected by the uncompensated gyro bias in vertical channel.

33 CFR 62.51 - Western Rivers Marking System.

Code of Federal Regulations, 2010 CFR

2010-07-01

... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.51 Western Rivers... toward the Gulf of Mexico. (b) The Western Rivers System varies from the standard U.S. system as follows...

33 CFR 62.51 - Western Rivers Marking System.

Code of Federal Regulations, 2011 CFR

2011-07-01

... NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.51 Western Rivers... toward the Gulf of Mexico. (b) The Western Rivers System varies from the standard U.S. system as follows...

NASA tracking ship navigation systems

NASA Technical Reports Server (NTRS)

Mckenna, J. J.

1976-01-01

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 broken down into its basic components. Particular emphasis is given to the inertial navigation system. Each navigation system used, a mariner star tracker, navigation satellite system, Loran C and OMEGA in conjunction with the inertial system is described. The accuracy of each system is compared along with their limitations.

An Agent-Based Model for Navigation Simulation in a Heterogeneous Environment

ERIC Educational Resources Information Center

Shanklin, Teresa A.

2012-01-01

Complex navigation (e.g. indoor and outdoor environments) can be studied as a system-of-systems problem. The model is made up of disparate systems that can aid a user in navigating from one location to another, utilizing whatever sensor system or information is available. By using intelligent navigation sensors and techniques (e.g. RFID, Wifi,…

33 CFR 62.47 - Sound signals.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Sound signals. 62.47 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

33 CFR 62.43 - Numbers and letters.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Section 62.43 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.43 Numbers and letters. (a) All solid red and solid green aids are numbered, with red aids bearing even numbers and green...

33 CFR 62.43 - Numbers and letters.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Section 62.43 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.43 Numbers and letters. (a) All solid red and solid green aids are numbered, with red aids bearing even numbers and green...

33 CFR 62.43 - Numbers and letters.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 62.43 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.43 Numbers and letters. (a) All solid red and solid green aids are numbered, with red aids bearing even numbers and green...

33 CFR 62.43 - Numbers and letters.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Section 62.43 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.43 Numbers and letters. (a) All solid red and solid green aids are numbered, with red aids bearing even numbers and green...

33 CFR 62.47 - Sound signals.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Sound signals. 62.47 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

33 CFR 62.47 - Sound signals.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Sound signals. 62.47 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

33 CFR 62.47 - Sound signals.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Sound signals. 62.47 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

33 CFR 62.47 - Sound signals.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Sound signals. 62.47 Section 62... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.47 Sound signals. (a) Often sound signals are located on or adjacent to aids to navigation. When visual signals are obscured...

Synergies in Astrometry: Predicting Navigational Error of Visual Binary Stars

NASA Astrophysics Data System (ADS)

Gessner Stewart, Susan

2015-08-01

Celestial navigation can employ a number of bright stars which are in binary systems. Often these are unresolved, appearing as a single, center-of-light object. A number of these systems are, however, in wide systems which could introduce a margin of error in the navigation solution if not handled properly. To illustrate the importance of good orbital solutions for binary systems - as well as good astrometry in general - the relationship between the center-of-light versus individual catalog position of celestial bodies and the error in terrestrial position derived via celestial navigation is demonstrated. From the list of navigational binary stars, fourteen such binary systems with at least 3.0 arcseconds apparent separation are explored. Maximum navigational error is estimated under the assumption that the bright star in the pair is observed at maximum separation, but the center-of-light is employed in the navigational solution. The relationships between navigational error and separation, orbital periods, and observers' latitude are discussed.

Guidance-Control-Navigation Automation for Night All-Weather Tactical Operations Held at Hague (Netherlands) on 21-24 May 1985.

DTIC Science & Technology

1985-11-01

1 1 f, 1,1"u’t I r -I irmat tor related to the weapon system as a whole can [1--1 Th t- it: as growth pot enS lal to Interface a Mission Planning...taictical decisions4 1n" 1 w 1I ’ depenid en the? core avionics to varying dog re-n. It is Important .i.h, h11~ knew whether any equipment or system ...toot en limitant le poids. le volume et le coOt des eguipements. Des fonctions nouvelles sont introduites. Peu A peu, le systeme de navigation se

Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Lab

NASA Technical Reports Server (NTRS)

Brewster, Linda L.; Howard, Richard T.; Johnston, A. S.; Carrington, Connie; Mitchell, Jennifer D.; Cryan, Scott P.

2008-01-01

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success ofthe Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor-proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-Ioop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of "pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL) using the FRL's 6-DOF gantry system, called the Dynamic Overhead Target System (DOTS). The target vehicle for "docking" in the laboratory was a mockup that was representative of the proposed CEV docking system, with added retroreflectors for the AVGS.' The multi-sensor test configuration used 35 open-loop test trajectories covering three major objectives: (l) sensor characterization trajectories designed to test a wide range of performance parameters; (2) CEV-specific trajectories designed to test performance during CEV-like approach and departure profiles; and (3) sensor characterization tests designed for evaluating sensor performance under more extreme conditions as might be induced during a spacecraft failure or during contingency situations. This paper describes the test development, test facility, test preparations, test execution, and test results of the multisensor series oftrajectories

Navigation ability dependent neural activation in the human brain: an fMRI study.

PubMed

Ohnishi, Takashi; Matsuda, Hiroshi; Hirakata, Makiko; Ugawa, Yoshikazu

2006-08-01

Visual-spatial navigation in familiar and unfamiliar environments is an essential requirement of daily life. Animal studies indicated the importance of the hippocampus for navigation. Neuroimaging studies demonstrated gender difference or strategies dependent difference of neural substrates for navigation. Using functional magnetic resonance imaging, we measured brain activity related to navigation in four groups of normal volunteers: good navigators (males and females) and poor navigators (males and females). In a whole group analysis, task related activity was noted in the hippocampus, parahippocampal gyrus, posterior cingulate cortex, precuneus, parietal association areas, and the visual association areas. In group comparisons, good navigators showed a stronger activation in the medial temporal area and precuneus than poor navigators. There was neither sex effect nor interaction effect between sex and navigation ability. The activity in the left medial temporal areas was positively correlated with task performance, whereas activity in the right parietal area was negatively correlated with task performance. Furthermore, the activity in the bilateral medial temporal areas was positively correlated with scores reflecting preferred navigation strategies, whereas activity in the bilateral superior parietal lobules was negatively correlated with them. Our data suggest that different brain activities related to navigation should reflect navigation skill and strategies.

Patient Navigation from the Paired Perspectives of Cancer Patients and Navigators: A Qualitative Analysis

PubMed Central

Yosha, Amanat M.; Carroll, Jennifer K.; Hendren, Samantha; Salamone, Charcy M.; Sanders, Mechelle; Fiscella, Kevin; Epstein, Ronald M.

2011-01-01

Objective Patient navigation for cancer care assesses and alleviates barriers to health care services. We examined paired perspectives of cancer patients and their navigators to examine the process of patient navigation. We explored the strengths, limitations, and our own lessons learned about adopting the novel methodology of multiperspective analysis. Methods As part of a larger RCT, patients and navigators were interviewed separately. We reviewed interviews with 18 patient-navigator dyads. Dyad summaries were created that explicitly incorporated both patient and navigator perspectives. Emerging themes and verbatim quotations were reflected in the summaries. Results Paired perspectives were valuable in identifying struggles that arose during navigation. These were represented as imbalanced investment and relational amelioration. Patients and navigators had general consensus about important patient needs for cancer care, but characterized these needs differently. Conclusion Our experience with multiperspective analysis revealed a methodology that delivers novel relational findings, but is best conducted de novo rather than as part of a larger study. Practice Implications Multiperspective analysis should be more widely adopted with clear aims and analytic strategy that strengthen the ability to reveal relational dynamics. Navigation training programs should anticipate navigator struggles and provide navigators with tools to manage them. PMID:21255958

Novel cemented cup-holding technique while performing total hip arthroplasty with navigation system.

PubMed

Takai, Hirokazu; Takahashi, Tomoki

2017-09-01

Recently, navigation systems have been more widely utilized in total hip arthroplasty. However, almost all of these systems have been developed for cementless cups. In the case of cemented total hip arthroplasty using a navigation system, a special-ordered cemented holder is needed. We propose a novel cemented cup-holding technique for navigation systems using readily available articles. We combine a cementless cup holder with an inverted cementless trial cup. The resulting apparatus is used as a cemented cup holder. The upside-down cup-holding technique is useful and permits cemented cup users to utilize a navigation system for placement of the acetabular component.

Accuracy of pedicle screw placement based on preoperative computed tomography versus intraoperative data set acquisition for spinal navigation system.

PubMed

Liu, Hao; Chen, Weikai; Liu, Tao; Meng, Bin; Yang, Huilin

2017-01-01

To investigate the accuracy of pedicle screw placement based on preoperative computed tomography in comparison with intraoperative data set acquisition for spinal navigation system. The PubMed (MEDLINE), EMBASE, and Web of Science were systematically searched for the literature published up to September 2015. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Statistical analysis was performed using the Review Manager 5.3. The dichotomous data for the pedicle violation rate was summarized using relative risk (RR) and 95% confidence intervals (CIs) with the fixed-effects model. The level of significance was set at p < 0.05. For this meta-analysis, seven studies used a total of 579 patients and 2981 screws. The results revealed that the accuracy of intraoperative data set acquisition method is significantly higher than preoperative one using 2 mm grading criteria (RR: 1.82, 95% CI: 1.09, 3.04, I 2 = 0%, p = 0.02). However, there was no significant difference between two kinds of methods at the 0 mm grading criteria (RR: 1.13, 95% CI: 0.88, 1.46, I 2 = 17%, p = 0.34). Using the 2-mm grading criteria, there was a higher accuracy of pedicle screw insertion in O-arm-assisted navigation than CT-based navigation method (RR: 1.96, 95% CI: 1.05, 3.64, I 2 = 0%, p = 0.03). The accuracy between CT-based navigation and two-dimensional-based navigation showed no significant difference (RR: 1.02, 95% CI: 0.35-3.03, I 2 = 0%, p = 0.97). The intraoperative data set acquisition method may decrease the incidence of perforated screws over 2 mm but not increase the number of screws fully contained within the pedicle compared to preoperative CT-based navigation system. A significantly higher accuracy of intraoperative (O-arm) than preoperative CT-based navigation was revealed using 2 mm grading criteria.

Free-Flight Terrestrial Rocket Lander Demonstration for NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) System

NASA Technical Reports Server (NTRS)

Rutishauser, David K.; Epp, Chirold; Robertson, Ed

2012-01-01

The Autonomous Landing Hazard Avoidance Technology (ALHAT) Project is chartered to develop and mature to a Technology Readiness Level (TRL) of six an autonomous system combining guidance, navigation and control with terrain sensing and recognition functions for crewed, cargo, and robotic planetary landing vehicles. The ALHAT System must be capable of identifying and avoiding surface hazards to enable a safe and accurate landing to within tens of meters of designated and certified landing sites anywhere on a planetary surface under any lighting conditions. Since its inception in 2006, the ALHAT Project has executed four field test campaigns to characterize and mature sensors and algorithms that support real-time hazard detection and global/local precision navigation for planetary landings. The driving objective for Government Fiscal Year 2012 (GFY2012) is to successfully demonstrate autonomous, real-time, closed loop operation of the ALHAT system in a realistic free flight scenario on Earth using the Morpheus lander developed at the Johnson Space Center (JSC). This goal represents an aggressive target consistent with a lean engineering culture of rapid prototyping and development. This culture is characterized by prioritizing early implementation to gain practical lessons learned and then building on this knowledge with subsequent prototyping design cycles of increasing complexity culminating in the implementation of the baseline design. This paper provides an overview of the ALHAT/Morpheus flight demonstration activities in GFY2012, including accomplishments, current status, results, and lessons learned. The ALHAT/Morpheus effort is also described in the context of a technology path in support of future crewed and robotic planetary exploration missions based upon the core sensing functions of the ALHAT system: Terrain Relative Navigation (TRN), Hazard Detection and Avoidance (HDA), and Hazard Relative Navigation (HRN).

Global Positioning System Bibliography

DTIC Science & Technology

1992-03-01

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

A Strapdown Interial Navigation System/Beidou/Doppler Velocity Log Integrated Navigation Algorithm Based on a Cubature Kalman Filter

PubMed Central

Gao, Wei; Zhang, Ya; Wang, Jianguo

2014-01-01

The integrated navigation system with strapdown inertial navigation system (SINS), Beidou (BD) receiver and Doppler velocity log (DVL) can be used in marine applications owing to the fact that the redundant and complementary information from different sensors can markedly improve the system accuracy. However, the existence of multisensor asynchrony will introduce errors into the system. In order to deal with the problem, conventionally the sampling interval is subdivided, which increases the computational complexity. In this paper, an innovative integrated navigation algorithm based on a Cubature Kalman filter (CKF) is proposed correspondingly. A nonlinear system model and observation model for the SINS/BD/DVL integrated system are established to more accurately describe the system. By taking multi-sensor asynchronization into account, a new sampling principle is proposed to make the best use of each sensor's information. Further, CKF is introduced in this new algorithm to enable the improvement of the filtering accuracy. The performance of this new algorithm has been examined through numerical simulations. The results have shown that the positional error can be effectively reduced with the new integrated navigation algorithm. Compared with the traditional algorithm based on EKF, the accuracy of the SINS/BD/DVL integrated navigation system is improved, making the proposed nonlinear integrated navigation algorithm feasible and efficient. PMID:24434842

Fuzzy adaptive interacting multiple model nonlinear filter for integrated navigation sensor fusion.

PubMed

Tseng, Chien-Hao; Chang, Chih-Wen; Jwo, Dah-Jing

2011-01-01

In this paper, the application of the fuzzy interacting multiple model unscented Kalman filter (FUZZY-IMMUKF) approach to integrated navigation processing for the maneuvering vehicle is presented. The unscented Kalman filter (UKF) employs a set of sigma points through deterministic sampling, such that a linearization process is not necessary, and therefore the errors caused by linearization as in the traditional extended Kalman filter (EKF) can be avoided. The nonlinear filters naturally suffer, to some extent, the same problem as the EKF for which the uncertainty of the process noise and measurement noise will degrade the performance. As a structural adaptation (model switching) mechanism, the interacting multiple model (IMM), which describes a set of switching models, can be utilized for determining the adequate value of process noise covariance. The fuzzy logic adaptive system (FLAS) is employed to determine the lower and upper bounds of the system noise through the fuzzy inference system (FIS). The resulting sensor fusion strategy can efficiently deal with the nonlinear problem for the vehicle navigation. The proposed FUZZY-IMMUKF algorithm shows remarkable improvement in the navigation estimation accuracy as compared to the relatively conventional approaches such as the UKF and IMMUKF.

33 CFR 62.27 - Safe water marks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Safe water marks. 62.27 Section... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.27 Safe water marks. Safe water marks indicate that there is navigable water all around the mark. They are often used to indicate...

33 CFR 62.27 - Safe water marks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Safe water marks. 62.27 Section... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.27 Safe water marks. Safe water marks indicate that there is navigable water all around the mark. They are often used to indicate...

33 CFR 62.27 - Safe water marks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Safe water marks. 62.27 Section... UNITED STATES AIDS TO NAVIGATION SYSTEM The U.S. Aids to Navigation System § 62.27 Safe water marks. Safe water marks indicate that there is navigable water all around the mark. They are often used to indicate...

Vision and visual navigation in nocturnal insects.

PubMed

Warrant, Eric; Dacke, Marie

2011-01-01

With their highly sensitive visual systems, nocturnal insects have evolved a remarkable capacity to discriminate colors, orient themselves using faint celestial cues, fly unimpeded through a complicated habitat, and navigate to and from a nest using learned visual landmarks. Even though the compound eyes of nocturnal insects are significantly more sensitive to light than those of their closely related diurnal relatives, their photoreceptors absorb photons at very low rates in dim light, even during demanding nocturnal visual tasks. To explain this apparent paradox, it is hypothesized that the necessary bridge between retinal signaling and visual behavior is a neural strategy of spatial and temporal summation at a higher level in the visual system. Exactly where in the visual system this summation takes place, and the nature of the neural circuitry that is involved, is currently unknown but provides a promising avenue for future research.

Image navigation as a means to expand the boundaries of fluorescence-guided surgery

NASA Astrophysics Data System (ADS)

Brouwer, Oscar R.; Buckle, Tessa; Bunschoten, Anton; Kuil, Joeri; Vahrmeijer, Alexander L.; Wendler, Thomas; Valdés-Olmos, Renato A.; van der Poel, Henk G.; van Leeuwen, Fijs W. B.

2012-05-01

Hybrid tracers that are both radioactive and fluorescent help extend the use of fluorescence-guided surgery to deeper structures. Such hybrid tracers facilitate preoperative surgical planning using (3D) scintigraphic images and enable synchronous intraoperative radio- and fluorescence guidance. Nevertheless, we previously found that improved orientation during laparoscopic surgery remains desirable. Here we illustrate how intraoperative navigation based on optical tracking of a fluorescence endoscope may help further improve the accuracy of hybrid surgical guidance. After feeding SPECT/CT images with an optical fiducial as a reference target to the navigation system, optical tracking could be used to position the tip of the fluorescence endoscope relative to the preoperative 3D imaging data. This hybrid navigation approach allowed us to accurately identify marker seeds in a phantom setup. The multispectral nature of the fluorescence endoscope enabled stepwise visualization of the two clinically approved fluorescent dyes, fluorescein and indocyanine green. In addition, the approach was used to navigate toward the prostate in a patient undergoing robot-assisted prostatectomy. Navigation of the tracked fluorescence endoscope toward the target identified on SPECT/CT resulted in real-time gradual visualization of the fluorescent signal in the prostate, thus providing an intraoperative confirmation of the navigation accuracy.

Magnetospheric Multiscale Mission (MMS) Phase 2B Navigation Performance

NASA Technical Reports Server (NTRS)

Scaperoth, Paige Thomas; Long, Anne; Carpenter, Russell

2009-01-01

The Magnetospheric Multiscale (MMS) formation flying mission, which consists of four spacecraft flying in a tetrahedral formation, has challenging navigation requirements associated with determining and maintaining the relative separations required to meet the science requirements. The baseline navigation concept for MMS is for each spacecraft to independently estimate its position, velocity and clock states using GPS pseudorange data provided by the Goddard Space Flight Center-developed Navigator receiver and maneuver acceleration measurements provided by the spacecraft's attitude control subsystem. State estimation is performed onboard in real-time using the Goddard Enhanced Onboard Navigation System flight software, which is embedded in the Navigator receiver. The current concept of operations for formation maintenance consists of a sequence of two maintenance maneuvers that is performed every 2 weeks. Phase 2b of the MMS mission, in which the spacecraft are in 1.2 x 25 Earth radii orbits with nominal separations at apogee ranging from 30 km to 400 km, has the most challenging navigation requirements because, during this phase, GPS signal acquisition is restricted to less than one day of the 2.8-day orbit. This paper summarizes the results from high-fidelity simulations to determine if the MMS navigation requirements can be met between and immediately following the maintenance maneuver sequence in Phase 2b.

The development of a white cane which navigates the visually impaired.

PubMed

Shiizu, Yuriko; Hirahara, Yoshiaki; Yanashima, Kenji; Magatani, Kazushige

2007-01-01

In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. This system is composed of colored navigation lines, RFID tags and an intelligent white cane. In our system, some colored marking tapes are set on along the walking route. These lines are called navigation line. And also RFID tags are set on this line at each landmark point. The intelligent white cane can sense a color of navigation line and receive tag information. By vibration of white cane, the system informs the visually impaired that he/she is walking along the navigation line. At the landmark point, the system also notifies area information to him/her by pre-recorded voice. Ten normal subjects who were blind folded with an eye mask were tested with this system. All of them were able to walk along the navigation line. The performance of the area information system was good. Therefore, we have concluded that our system will be extremely valuable in supporting the activities of the visually impaired.

Navigation technique for MR-endoscope system using a wireless accelerometer-based remote control device.

PubMed

Kumamoto, Etsuko; Takahashi, Akihiro; Matsuoka, Yuichiro; Morita, Yoshinori; Kutsumi, Hiromu; Azuma, Takeshi; Kuroda, Kagayaki

2013-01-01

The MR-endoscope system can perform magnetic resonance (MR) imaging during endoscopy and show the images obtained by using endoscope and MR. The MR-endoscope system can acquire a high-spatial resolution MR image with an intraluminal radiofrequency (RF) coil, and the navigation system shows the scope's location and orientation inside the human body and indicates MR images with a scope view. In order to conveniently perform an endoscopy and MR procedure, the design of the user interface is very important because it provides useful information. In this study, we propose a navigation system using a wireless accelerometer-based controller with Bluetooth technology and a navigation technique to set the intraluminal RF coil using the navigation system. The feasibility of using this wireless controller in the MR shield room was validated via phantom examinations of the influence on MR procedures and navigation accuracy. In vitro examinations using an isolated porcine stomach demonstrated the effectiveness of the navigation technique using a wireless remote-control device.

33 CFR 169.100 - What mandatory ship reporting systems are established by this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What mandatory ship reporting systems are established by this subpart? 169.100 Section 169.100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Establishment of Two Mandatory Ship Reporting...

Impact Assessment of GNSS Spoofing Attacks on INS/GNSS Integrated Navigation System.

PubMed

Liu, Yang; Li, Sihai; Fu, Qiangwen; Liu, Zhenbo

2018-05-04

In the face of emerging Global Navigation Satellite System (GNSS) spoofing attacks, there is a need to give a comprehensive analysis on how the inertial navigation system (INS)/GNSS integrated navigation system responds to different kinds of spoofing attacks. A better understanding of the integrated navigation system’s behavior with spoofed GNSS measurements gives us valuable clues to develop effective spoofing defenses. This paper focuses on an impact assessment of GNSS spoofing attacks on the integrated navigation system Kalman filter’s error covariance, innovation sequence and inertial sensor bias estimation. A simple and straightforward measurement-level trajectory spoofing simulation framework is presented, serving as the basis for an impact assessment of both unsynchronized and synchronized spoofing attacks. Recommendations are given for spoofing detection and mitigation based on our findings in the impact assessment process.

Conceptual Design of a Communication-Based Deep Space Navigation Network

NASA Technical Reports Server (NTRS)

Anzalone, Evan J.; Chuang, C. H.

2012-01-01

As the need grows for increased autonomy and position knowledge accuracy to support missions beyond Earth orbit, engineers must push and develop more advanced navigation sensors and systems that operate independent of Earth-based analysis and processing. Several spacecraft are approaching this problem using inter-spacecraft radiometric tracking and onboard autonomous optical navigation methods. This paper proposes an alternative implementation to aid in spacecraft position fixing. The proposed method Network-Based Navigation technique takes advantage of the communication data being sent between spacecraft and between spacecraft and ground control to embed navigation information. The navigation system uses these packets to provide navigation estimates to an onboard navigation filter to augment traditional ground-based radiometric tracking techniques. As opposed to using digital signal measurements to capture inherent information of the transmitted signal itself, this method relies on the embedded navigation packet headers to calculate a navigation estimate. This method is heavily dependent on clock accuracy and the initial results show the promising performance of a notional system.

Spatial Navigation Impairments Among Intellectually High-Functioning Adults With Autism Spectrum Disorder: Exploring Relations With Theory of Mind, Episodic Memory, and Episodic Future Thinking

PubMed Central

2013-01-01

Research suggests that spatial navigation relies on the same neural network as episodic memory, episodic future thinking, and theory of mind (ToM). Such findings have stimulated theories (e.g., the scene construction and self-projection hypotheses) concerning possible common underlying cognitive capacities. Consistent with such theories, autism spectrum disorder (ASD) is characterized by concurrent impairments in episodic memory, episodic future thinking, and ToM. However, it is currently unclear whether spatial navigation is also impaired. Hence, ASD provides a test case for the scene construction and self-projection theories. The study of spatial navigation in ASD also provides a test of the extreme male brain theory of ASD, which predicts intact or superior navigation (purportedly a systemizing skill) performance among individuals with ASD. Thus, the aim of the current study was to establish whether spatial navigation in ASD is impaired, intact, or superior. Twenty-seven intellectually high-functioning adults with ASD and 28 sex-, age-, and IQ-matched neurotypical comparison adults completed the memory island virtual navigation task. Tests of episodic memory, episodic future thinking, and ToM were also completed. Participants with ASD showed significantly diminished performance on the memory island task, and performance was positively related to ToM and episodic memory, but not episodic future thinking. These results suggest that (contra the extreme male brain theory) individuals with ASD have impaired survey-based navigation skills—that is, difficulties generating cognitive maps of the environment—and adds weight to the idea that scene construction/self-projection are impaired in ASD. The theoretical and clinical implications of these results are discussed. PMID:24364620

Quantitative knowledge acquisition for expert systems

NASA Technical Reports Server (NTRS)

Belkin, Brenda L.; Stengel, Robert F.

1991-01-01

A common problem in the design of expert systems is the definition of rules from data obtained in system operation or simulation. While it is relatively easy to collect data and to log the comments of human operators engaged in experiments, generalizing such information to a set of rules has not previously been a direct task. A statistical method is presented for generating rule bases from numerical data, motivated by an example based on aircraft navigation with multiple sensors. The specific objective is to design an expert system that selects a satisfactory suite of measurements from a dissimilar, redundant set, given an arbitrary navigation geometry and possible sensor failures. The systematic development is described of a Navigation Sensor Management (NSM) Expert System from Kalman Filter convariance data. The method invokes two statistical techniques: Analysis of Variance (ANOVA) and the ID3 Algorithm. The ANOVA technique indicates whether variations of problem parameters give statistically different covariance results, and the ID3 algorithms identifies the relationships between the problem parameters using probabilistic knowledge extracted from a simulation example set. Both are detailed.

Autonomous Wheeled Robot Platform Testbed for Navigation and Mapping Using Low-Cost Sensors

NASA Astrophysics Data System (ADS)

Calero, D.; Fernandez, E.; Parés, M. E.

2017-11-01

This paper presents the concept of an architecture for a wheeled robot system that helps researchers in the field of geomatics to speed up their daily research on kinematic geodesy, indoor navigation and indoor positioning fields. The presented ideas corresponds to an extensible and modular hardware and software system aimed at the development of new low-cost mapping algorithms as well as at the evaluation of the performance of sensors. The concept, already implemented in the CTTC's system ARAS (Autonomous Rover for Automatic Surveying) is generic and extensible. This means that it is possible to incorporate new navigation algorithms or sensors at no maintenance cost. Only the effort related to the development tasks required to either create such algorithms needs to be taken into account. As a consequence, change poses a much small problem for research activities in this specific area. This system includes several standalone sensors that may be combined in different ways to accomplish several goals; that is, this system may be used to perform a variety of tasks, as, for instance evaluates positioning algorithms performance or mapping algorithms performance.

Tuning and Robustness Analysis for the Orion Absolute Navigation System

NASA Technical Reports Server (NTRS)

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

2013-01-01

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 ight, 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 modi cations since its inception, and continues as a work-in-progress. This paper seeks to show the e orts made to-date in tuning the lter for the EFT-1 mission and instilling appropriate robustness into the system to meet the requirements of manned space ight. The results generally show Monte Carlo error performance bounded by the lter uncertainty for all phases of ight. Some future items of investigation are presented related to suspected anomalies in the trajectory truth reference le.

Maritime Navigation/Communications Program. Volume 1. Navigation and Communications System Study.

DOT National Transportation Integrated Search

1984-10-01

A Maritime Administration/Transportation Systems Center team has been conducting a program to study navigation and communication systems on the Great Lakes and St. Lawrence River with the objective of defining technologies and systems that have the p...

33 CFR 149.419 - Can the water supply for the helicopter deck fire protection system be part of a fire water system?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Can the water supply for the helicopter deck fire protection system be part of a fire water system? 149.419 Section 149.419 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND EQUIPMENT...

33 CFR 149.419 - Can the water supply for the helicopter deck fire protection system be part of a fire water system?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Can the water supply for the helicopter deck fire protection system be part of a fire water system? 149.419 Section 149.419 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND EQUIPMENT...

33 CFR 149.419 - Can the water supply for the helicopter deck fire protection system be part of a fire water system?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Can the water supply for the helicopter deck fire protection system be part of a fire water system? 149.419 Section 149.419 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND EQUIPMENT...

33 CFR 149.419 - Can the water supply for the helicopter deck fire protection system be part of a fire water system?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Can the water supply for the helicopter deck fire protection system be part of a fire water system? 149.419 Section 149.419 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DEEPWATER PORTS DEEPWATER PORTS: DESIGN, CONSTRUCTION, AND EQUIPMENT...

Preliminary Design of the Guidance, Navigation, and Control System of the Altair Lunar Lander

NASA Technical Reports Server (NTRS)

Lee, Allan Y.; Ely, Todd; Sostaric, Ronald; Strahan, Alan; Riedel, Joseph E.; Ingham, Mitch; Wincentsen, James; Sarani, Siamak

2010-01-01

Guidance, Navigation, and Control (GN&C) is the measurement and control of spacecraft position, velocity, and attitude in support of mission objectives. This paper provides an overview of a preliminary design of the GN&C system of the Lunar Lander Altair. Key functions performed by the GN&C system in various mission phases will first be described. A set of placeholder GN&C sensors that is needed to support these functions is next described. To meet Crew safety requirements, there must be high degrees of redundancy in the selected sensor configuration. Two sets of thrusters, one on the Ascent Module (AM) and the other on the Descent Module (DM), will be used by the GN&C system. The DM thrusters will be used, among other purposes, to perform course correction burns during the Trans-lunar Coast. The AM thrusters will be used, among other purposes, to perform precise angular and translational controls of the ascent module in order to dock the ascent module with Orion. Navigation is the process of measurement and control of the spacecraft's "state" (both the position and velocity vectors of the spacecraft). Tracking data from the Earth-Based Ground System (tracking antennas) as well as data from onboard optical sensors will be used to estimate the vehicle state. A driving navigation requirement is to land Altair on the Moon with a landing accuracy that is better than 1 km (radial 95%). Preliminary performance of the Altair GN&C design, relative to this and other navigation requirements, will be given. Guidance is the onboard process that uses the estimated state vector, crew inputs, and pre-computed reference trajectories to guide both the rotational and the translational motions of the spacecraft during powered flight phases. Design objectives of reference trajectories for various mission phases vary. For example, the reference trajectory for the descent "approach" phase (the last 3-4 minutes before touchdown) will sacrifice fuel utilization efficiency in order to provide landing site visibility for both the crew and the terrain hazard detection sensor system. One output of Guidance is the steering angle commands sent to the 2 degree-of-freedom (dof) gimbal actuation system of the descent engine. The engine gimbal actuation system is controlled by a Thrust Vector Control algorithm that is designed taking into account the large quantities of sloshing liquids in tanks mounted on Altair. In this early design phase of Altair, the GN&C system is described only briefly in this paper and the emphasis is on the GN&C architecture (that is still evolving). Multiple companion papers will provide details that are related to navigation, optical navigation, guidance, fuel sloshing, rendezvous and docking, machine-pilot interactions, and others. The similarities and differences of GN&C designs for Lunar and Mars landers are briefly compared.

X-Ray Detection and Processing Models for Spacecraft Navigation and Timing

NASA Technical Reports Server (NTRS)

Sheikh, Suneel; Hanson, John

2013-01-01

The current primary method of deepspace navigation is the NASA Deep Space Network (DSN). High-performance navigation is achieved using Delta Differential One-Way Range techniques that utilize simultaneous observations from multiple DSN sites, and incorporate observations of quasars near the line-of-sight to a spacecraft in order to improve the range and angle measurement accuracies. Over the past four decades, x-ray astronomers have identified a number of xray pulsars with pulsed emissions having stabilities comparable to atomic clocks. The x-ray pulsar-based navigation and time determination (XNAV) system uses phase measurements from these sources to establish autonomously the position of the detector, and thus the spacecraft, relative to a known reference frame, much as the Global Positioning System (GPS) uses phase measurements from radio signals from several satellites to establish the position of the user relative to an Earth-centered fixed frame of reference. While a GPS receiver uses an antenna to detect the radio signals, XNAV uses a detector array to capture the individual xray photons from the x-ray pulsars. The navigation solution relies on detailed xray source models, signal processing, navigation and timing algorithms, and analytical tools that form the basis of an autonomous XNAV system. Through previous XNAV development efforts, some techniques have been established to utilize a pulsar pulse time-of-arrival (TOA) measurement to correct a position estimate. One well-studied approach, based upon Kalman filter methods, optimally adjusts a dynamic orbit propagation solution based upon the offset in measured and predicted pulse TOA. In this delta position estimator scheme, previously estimated values of spacecraft position and velocity are utilized from an onboard orbit propagator. Using these estimated values, the detected arrival times at the spacecraft of pulses from a pulsar are compared to the predicted arrival times defined by the pulsar s pulse timing model. A discrepancy provides an estimate of the spacecraft position offset, since an error in position will relate to the measured time offset of a pulse along the line of sight to the pulsar. XNAV researchers have been developing additional enhanced approaches to process the photon TOAs to arrive at an estimate of spacecraft position, including those using maximum-likelihood estimation, digital phase locked loops, and "single photon processing" schemes that utilize all available time data associated with each photon. Using pulsars from separate, non-coplanar locations provides range and range-rate measurements in each pulsar s direction. Combining these different pulsar measurements solves for offsets in position and velocity in three dimensions, and provides accurate overall navigation for deep space vehicles.

National aerospace meeting of the Institute of Navigation

NASA Astrophysics Data System (ADS)

Fell, Patrick

The program for this year's aerospace meeting of The Institute of Navigation addressed developments in the evolving Global Positioning System (GPS) of navigation satellites, inertial navigation systems, and other electronic navigation systems and their applications. Also included in the program were a limited number of papers addressing the geodetic use of the GPS system.The Global Positioning System is a constellation of 18 navigation satellites being developed by the Department of Defense to provide instantaneous worldwide navigation. The system will support a multitude of military applications. The first paper by Jacobson reviewed the engineering development of GPS navigation receivers stressing the use of common hardware and software modules. A later paper by Ould described the mechanization of a digital receiver for GPS applications designed for faster acquisition of the spread spectrum satellite transmissions than analog receivers. The paper by Brady discussed the worldwide coverage that is provided by the limited number of satellites that will constitute the GPS constellation through 1983. The capability provided by the satellites presently on orbit would support a variety of experiments at almost any location. Tables of multiple satellite availability are provided for numerous worldwide locations. For civil aviation applications, Vogel addressed the satellite geometry considerations for low cost GPS user equipment, Esposito described the Federal Aviation Administration acceptance tests of a GPS navigation receiver, and Hopkins discussed the design and capability of an integrated GPS strapdown attitude and heading reference system for avionics.

Validation of Inertial and Optical Navigation Techniques for Space Applications with UAVS

NASA Astrophysics Data System (ADS)

Montaño, J.; Wis, M.; Pulido, J. A.; Latorre, A.; Molina, P.; Fernández, E.; Angelats, E.; Colomina, I.

2015-09-01

PERIGEO is an R&D project, funded by the INNPRONTA 2011-2014 programme from Spanish CDTI, which aims to investigate the use of UAV technologies and processes for the validation of space oriented technologies. For this purpose, among different space missions and technologies, a set of activities for absolute and relative navigation are being carried out to deal with the attitude and position estimation problem from a temporal image sequence from a camera on the visible spectrum and/or Light Detection and Ranging (LIDAR) sensor. The process is covered entirely: from sensor measurements and data acquisition (images, LiDAR ranges and angles), data pre-processing (calibration and co-registration of camera and LIDAR data), features and landmarks extraction from the images and image/LiDAR-based state estimation. In addition to image processing area, classical navigation system based on inertial sensors is also included in the research. The reason of combining both approaches is to enable the possibility to keep navigation capability in environments or missions where the radio beacon or reference signal as the GNSS satellite is not available (as for example an atmospheric flight in Titan). The rationale behind the combination of those systems is that they complement each other. The INS is capable of providing accurate position, velocity and full attitude estimations at high data rates. However, they need an absolute reference observation to compensate the time accumulative errors caused by inertial sensor inaccuracies. On the other hand, imaging observables can provide absolute and relative positioning and attitude estimations. However they need that the sensor head is pointing toward ground (something that may not be possible if the carrying platform is maneuvering) to provide accurate estimations and they are not capable of provide some hundreds of Hz that can deliver an INS. This mutual complementarity has been observed in PERIGEO and because of this they are combined into one system. The inertial navigation system implemented in PERIGEO is based on a classical loosely coupled INS/GNSS approach that is very similar to the implementation of the INS/Imaging navigation system that is mentioned above. The activities envisaged in PERIGEO cover the algorithms development and validation and technology testing on UAVs under representative conditions. Past activities have covered the design and development of the algorithms and systems. This paper presents the most recent activities and results on the area of image processing for robust estimation within PERIGEO, which are related with the hardware platforms definition (including sensors) and its integration in UAVs. Results for the tests performed during the flight campaigns in representative outdoor environments will be also presented (at the time of the full paper submission the tests will be performed), as well as analyzed, together with a roadmap definition for future developments.

Autonomous Navigation Above the GNSS Constellations and Beyond: GPS Navigation for the Magnetospheric Multiscale Mission and SEXTANT Pulsar Navigation Demonstration

NASA Technical Reports Server (NTRS)

Winternitz, Luke

2017-01-01

This talk will describe two first-of-their-kind technology demonstrations attached to ongoing NASA science missions, both of which aim to extend the range of autonomous spacecraft navigation far from the Earth. First, we will describe the onboard GPS navigation system for the Magnetospheric Multiscale (MMS) mission which is currently operating in elliptic orbits reaching nearly halfway to the Moon. The MMS navigation system is a key outgrowth of a larger effort at NASA Goddard Space Flight Center to advance high-altitude Global Navigation Satellite System (GNSS) navigation on multiple fronts, including developing Global Positioning System receivers and onboard navigation software, running simulation studies, and leading efforts to characterize and protect signals at high-altitude in the so-called GNSS Space-Service Volume (SSV). In the second part of the talk, we will describe the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) mission that aims to make the first in-space demonstration of X-ray pulsar navigation (XNAV). SEXTANT is attached to the NASA astrophysics mission Neutron-star Interior Composition ExploreR (NICER) whose International Space Station mounted X-ray telescope is investigating the fundamental physics of extremes in gravity, material density, and electromagnetic fields found in neutron stars, and whose instrument provides a nearly ideal navigation sensor for XNAV.

Steering intermediate courses: desert ants combine information from various navigational routines.

PubMed

Wehner, Rüdiger; Hoinville, Thierry; Cruse, Holk; Cheng, Ken

2016-07-01

A number of systems of navigation have been studied in some detail in insects. These include path integration, a system that keeps track of the straight-line distance and direction travelled on the current trip, the use of panoramic landmarks and scenery for orientation, and systematic searching. A traditional view is that only one navigational system is in operation at any one time, with different systems running in sequence depending on the context and conditions. We review selected data suggesting that often, different navigational cues (e.g., compass cues) and different systems of navigation are in operation simultaneously in desert ant navigation. The evidence suggests that all systems operate in parallel forming a heterarchical network. External and internal conditions determine the weights to be accorded to each cue and system. We also show that a model of independent modules feeding into a central summating device, the Navinet model, can in principle account for such data. No central executive processor is necessary aside from a weighted summation of the different cues and systems. Such a heterarchy of parallel systems all in operation represents a new view of insect navigation that has already been expressed informally by some authors.

The Development of a Simulator System and Hardware Test Bed for Deep Space X-Ray Navigation

NASA Astrophysics Data System (ADS)

Doyle, Patrick T.

2013-03-01

Currently, there is a considerable interest in developing technologies that will allow using photon measurements from celestial x-ray sources for deep space navigation. The impetus for this is that many envisioned future space missions will require spacecraft to have autonomous navigation capabilities. For missions close to Earth, Global Navigation Satellite Systems (GNSS) such as GPS are readily available for use, but for missions far from Earth, other alternatives must be provided. While existing systems such as the Deep Space Network (DSN) can be used, latencies associated with servicing a fleet of vehicles may not be compatible with some autonomous operations requiring timely updates of their navigation solution. Because of their somewhat predictable emissions, pulsars are the ideal candidates for x-ray sources that can be used to provide key parameters for navigation. Algorithms and simulation tools that will enable designing and analyzing x-ray navigation concepts are presented. The development of a compact x-ray detector system is pivotal to the eventual deployment of such navigation systems. Therefore, results of a high altitude balloon test to evaluate the design of a compact x-ray detector system are described as well.

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

NASA Technical Reports Server (NTRS)

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

1997-01-01

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.

A Bionic Camera-Based Polarization Navigation Sensor

PubMed Central

Wang, Daobin; Liang, Huawei; Zhu, Hui; Zhang, Shuai

2014-01-01

Navigation and positioning technology is closely related to our routine life activities, from travel to aerospace. Recently it has been found that Cataglyphis (a kind of desert ant) is able to detect the polarization direction of skylight and navigate according to this information. This paper presents a real-time bionic camera-based polarization navigation sensor. This sensor has two work modes: one is a single-point measurement mode and the other is a multi-point measurement mode. An indoor calibration experiment of the sensor has been done under a beam of standard polarized light. The experiment results show that after noise reduction the accuracy of the sensor can reach up to 0.3256°. It is also compared with GPS and INS (Inertial Navigation System) in the single-point measurement mode through an outdoor experiment. Through time compensation and location compensation, the sensor can be a useful alternative to GPS and INS. In addition, the sensor also can measure the polarization distribution pattern when it works in multi-point measurement mode. PMID:25051029

BatSLAM: Simultaneous localization and mapping using biomimetic sonar.

PubMed

Steckel, Jan; Peremans, Herbert

2013-01-01

We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building.

BatSLAM: Simultaneous Localization and Mapping Using Biomimetic Sonar

PubMed Central

Steckel, Jan; Peremans, Herbert

2013-01-01

We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building. PMID:23365647

Comparison of free-hand fluoroscopic guidance and electromagnetic navigation in distal locking of femoral intramedullary nails

PubMed Central

Han, Bing; Shi, Zhigang; Fu, Yu; Ye, Yong; Jing, Juehua; Li, Jun

2017-01-01

Abstract Background: Although the method has been used widely, one of the greatest challenges for intramedullary nailing is to position the distal locking screw. A new technology, the electromagnetic navigation system, is a radiation-free way to locate the position of the drill bit and provide 3-dimensional real-time feedback of location and orientation of the drill bit relative to the locking holes. The purpose of our study was to evaluate the reliability and efficiency of the free-hand technique compared to the new electromagnetic navigation system. Methods: Fifty-four patients with femoral fracture who needed treatment with intramedullary nails were divided into 2 groups. One group including 26 patients underwent distal locking using the standard free-hand method, whereas the electromagnetic navigation system was used with the other 29 patients. Intraoperative fluoroscopy exposure times, screw insertion times, and healing times were recorded; these parameters were used for comparison between the 2 groups. Results: There were 17 males and 9 females who had femoral intramedullary nails using the free-hand technique, whereas 21 males and 8 females received intramedullary nails using the electromagnetic navigation system. The mean time of distal locking was 19.5 ± 6.0 minutes in the free-hand (FH) group, whereas the time was 6.1 ± 1.4 minutes in the electromagnetic (ET) group. The exposure time for the FH group was 26.8 ± 13.3 seconds and 2.2 ± 1.1 seconds for the ET group. Healing time proved to be comparable in the FH and ET groups (16.4 ± 3.7 weeks vs 15.1 ± 2.8 weeks). Conclusion: Under the premise of achieving the same effect, the electromagnetic navigation system has the advantage of less distal locking time and less radiation dose. PMID:28723755

Comparison of free-hand fluoroscopic guidance and electromagnetic navigation in distal locking of femoral intramedullary nails.

PubMed

Han, Bing; Shi, Zhigang; Fu, Yu; Ye, Yong; Jing, Juehua; Li, Jun

2017-07-01

Although the method has been used widely, one of the greatest challenges for intramedullary nailing is to position the distal locking screw. A new technology, the electromagnetic navigation system, is a radiation-free way to locate the position of the drill bit and provide 3-dimensional real-time feedback of location and orientation of the drill bit relative to the locking holes. The purpose of our study was to evaluate the reliability and efficiency of the free-hand technique compared to the new electromagnetic navigation system. Fifty-four patients with femoral fracture who needed treatment with intramedullary nails were divided into 2 groups. One group including 26 patients underwent distal locking using the standard free-hand method, whereas the electromagnetic navigation system was used with the other 29 patients. Intraoperative fluoroscopy exposure times, screw insertion times, and healing times were recorded; these parameters were used for comparison between the 2 groups. There were 17 males and 9 females who had femoral intramedullary nails using the free-hand technique, whereas 21 males and 8 females received intramedullary nails using the electromagnetic navigation system. The mean time of distal locking was 19.5 ± 6.0 minutes in the free-hand (FH) group, whereas the time was 6.1 ± 1.4 minutes in the electromagnetic (ET) group. The exposure time for the FH group was 26.8 ± 13.3 seconds and 2.2 ± 1.1 seconds for the ET group. Healing time proved to be comparable in the FH and ET groups (16.4 ± 3.7 weeks vs 15.1 ± 2.8 weeks). Under the premise of achieving the same effect, the electromagnetic navigation system has the advantage of less distal locking time and less radiation dose.

The Deep Space Network. An instrument for radio navigation of deep space probes

NASA Technical Reports Server (NTRS)

Renzetti, N. A.; Jordan, J. F.; Berman, A. L.; Wackley, J. A.; Yunck, T. P.

1982-01-01

The Deep Space Network (DSN) network configurations used to generate the navigation observables and the basic process of deep space spacecraft navigation, from data generation through flight path determination and correction are described. Special emphasis is placed on the DSN Systems which generate the navigation data: the DSN Tracking and VLBI Systems. In addition, auxiliary navigational support functions are described.

33 CFR 183.507 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false General. 183.507 Section 183.507 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems General § 183.507 General. Each fuel system component on a boat...

33 CFR 155.230 - Emergency control systems for tank barges.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Emergency control systems for tank barges. 155.230 Section 155.230 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

33 CFR 155.230 - Emergency control systems for tank barges.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Emergency control systems for tank barges. 155.230 Section 155.230 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

33 CFR 155.230 - Emergency control systems for tank barges.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Emergency control systems for tank barges. 155.230 Section 155.230 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

33 CFR 155.230 - Emergency control systems for tank barges.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Emergency control systems for tank barges. 155.230 Section 155.230 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION OIL OR HAZARDOUS MATERIAL POLLUTION PREVENTION REGULATIONS FOR...

Indoor navigation by image recognition

NASA Astrophysics Data System (ADS)

Choi, Io Teng; Leong, Chi Chong; Hong, Ka Wo; Pun, Chi-Man

2017-07-01

With the progress of smartphones hardware, it is simple on smartphone using image recognition technique such as face detection. In addition, indoor navigation system development is much slower than outdoor navigation system. Hence, this research proves a usage of image recognition technique for navigation in indoor environment. In this paper, we introduced an indoor navigation application that uses the indoor environment features to locate user's location and a route calculating algorithm to generate an appropriate path for user. The application is implemented on Android smartphone rather than iPhone. Yet, the application design can also be applied on iOS because the design is implemented without using special features only for Android. We found that digital navigation system provides better and clearer location information than paper map. Also, the indoor environment is ideal for Image recognition processing. Hence, the results motivate us to design an indoor navigation system using image recognition.

A 3D Model Based Imdoor Navigation System for Hubei Provincial Museum

NASA Astrophysics Data System (ADS)

Xu, W.; Kruminaite, M.; Onrust, B.; Liu, H.; Xiong, Q.; Zlatanova, S.

2013-11-01

3D models are more powerful than 2D maps for indoor navigation in a complicate space like Hubei Provincial Museum because they can provide accurate descriptions of locations of indoor objects (e.g., doors, windows, tables) and context information of these objects. In addition, the 3D model is the preferred navigation environment by the user according to the survey. Therefore a 3D model based indoor navigation system is developed for Hubei Provincial Museum to guide the visitors of museum. The system consists of three layers: application, web service and navigation, which is built to support localization, navigation and visualization functions of the system. There are three main strengths of this system: it stores all data needed in one database and processes most calculations on the webserver which make the mobile client very lightweight, the network used for navigation is extracted semi-automatically and renewable, the graphic user interface (GUI), which is based on a game engine, has high performance of visualizing 3D model on a mobile display.

Spoofing Detection Using GNSS/INS/Odometer Coupling for Vehicular Navigation

PubMed Central

Broumandan, Ali; Lachapelle, Gérard

2018-01-01

Location information is one of the most vital information required to achieve intelligent and context-aware capability for various applications such as driverless cars. However, related security and privacy threats are a major holdback. With increasing focus on using Global Navigation Satellite Systems (GNSS) for autonomous navigation and related applications, it is important to provide robust navigation solutions, yet signal spoofing for illegal or covert transportation and misleading receiver timing is increasing and now frequent. Hence, detection and mitigation of spoofing attacks has become an important topic. Several contributions on spoofing detection have been made, focusing on different layers of a GNSS receiver. This paper focuses on spoofing detection utilizing self-contained sensors, namely inertial measurement units (IMUs) and vehicle odometer outputs. A spoofing detection approach based on a consistency check between GNSS and IMU/odometer mechanization is proposed. To detect a spoofing attack, the method analyses GNSS and IMU/odometer measurements independently during a pre-selected observation window and cross checks the solutions provided by GNSS and inertial navigation solution (INS)/odometer mechanization. The performance of the proposed method is verified in real vehicular environments. Mean spoofing detection time and detection performance in terms of receiver operation characteristics (ROC) in sub-urban and dense urban environments are evaluated. PMID:29695064

Spoofing Detection Using GNSS/INS/Odometer Coupling for Vehicular Navigation.

PubMed

Broumandan, Ali; Lachapelle, Gérard

2018-04-24

Location information is one of the most vital information required to achieve intelligent and context-aware capability for various applications such as driverless cars. However, related security and privacy threats are a major holdback. With increasing focus on using Global Navigation Satellite Systems (GNSS) for autonomous navigation and related applications, it is important to provide robust navigation solutions, yet signal spoofing for illegal or covert transportation and misleading receiver timing is increasing and now frequent. Hence, detection and mitigation of spoofing attacks has become an important topic. Several contributions on spoofing detection have been made, focusing on different layers of a GNSS receiver. This paper focuses on spoofing detection utilizing self-contained sensors, namely inertial measurement units (IMUs) and vehicle odometer outputs. A spoofing detection approach based on a consistency check between GNSS and IMU/odometer mechanization is proposed. To detect a spoofing attack, the method analyses GNSS and IMU/odometer measurements independently during a pre-selected observation window and cross checks the solutions provided by GNSS and inertial navigation solution (INS)/odometer mechanization. The performance of the proposed method is verified in real vehicular environments. Mean spoofing detection time and detection performance in terms of receiver operation characteristics (ROC) in sub-urban and dense urban environments are evaluated.

Field evaluation of a wearable multimodal soldier navigation system.

PubMed

Aaltonen, Iina; Laarni, Jari

2017-09-01

Challenging environments pose difficulties for terrain navigation, and therefore wearable and multimodal navigation systems have been proposed to overcome these difficulties. Few such navigation systems, however, have been evaluated in field conditions. We evaluated how a multimodal system can aid in navigating in a forest in the context of a military exercise. The system included a head-mounted display, headphones, and a tactile vibrating vest. Visual, auditory, and tactile modalities were tested and evaluated using unimodal, bimodal, and trimodal conditions. Questionnaires, interviews and observations were used to evaluate the advantages and disadvantages of each modality and their multimodal use. The guidance was considered easy to interpret and helpful in navigation. Simplicity of the displayed information was required, which was partially conflicting with the request for having both distance and directional information available. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations

PubMed Central

Cheng, Xuemin; Yang, Yikang; Hao, Qun

2016-01-01

The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1–5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control. PMID:27763515

Analysis of the Effects of Thermal Environment on Optical Systems for Navigation Guidance and Control in Supersonic Aircraft Based on Empirical Equations.

PubMed

Cheng, Xuemin; Yang, Yikang; Hao, Qun

2016-10-17

The thermal environment is an important factor in the design of optical systems. This study investigated the thermal analysis technology of optical systems for navigation guidance and control in supersonic aircraft by developing empirical equations for the front temperature gradient and rear thermal diffusion distance, and for basic factors such as flying parameters and the structure of the optical system. Finite element analysis (FEA) was used to study the relationship between flying and front dome parameters and the system temperature field. Systematic deduction was then conducted based on the effects of the temperature field on the physical geometry and ray tracing performance of the front dome and rear optical lenses, by deriving the relational expressions between the system temperature field and the spot size and positioning precision of the rear optical lens. The optical systems used for navigation guidance and control in supersonic aircraft when the flight speed is in the range of 1-5 Ma were analysed using the derived equations. Using this new method it was possible to control the precision within 10% when considering the light spot received by the four-quadrant detector, and computation time was reduced compared with the traditional method of separately analysing the temperature field of the front dome and rear optical lens using FEA. Thus, the method can effectively increase the efficiency of parameter analysis and computation in an airborne optical system, facilitating the systematic, effective and integrated thermal analysis of airborne optical systems for navigation guidance and control.

Autonomous navigation system. [gyroscopic pendulum for air navigation

NASA Technical Reports Server (NTRS)

Merhav, S. J. (Inventor)

1981-01-01

An inertial navigation system utilizing a servo-controlled two degree of freedom pendulum to obtain specific force components in the locally level coordinate system is described. The pendulum includes a leveling gyroscope and an azimuth gyroscope supported on a two gimbal system. The specific force components in the locally level coordinate system are converted to components in the geographical coordinate system by means of a single Euler transformation. The standard navigation equations are solved to determine longitudinal and lateral velocities. Finally, vehicle position is determined by a further integration.

Computer-assisted hip and knee arthroplasty. Navigation and active robotic systems: an evidence-based analysis.

PubMed

2004-01-01

The Medical Advisory Secretariat undertook a review of the evidence on the effectiveness and cost-effectiveness of computer assisted hip and knee arthroplasty. The two computer assisted arthroplasty systems that are the topics of this review are (1) navigation and (2) robotic-assisted hip and knee arthroplasty. Computer-assisted arthroplasty consists of navigation and robotic systems. Surgical navigation is a visualization system that provides positional information about surgical tools or implants relative to a target bone on a computer display. Most of the navigation-assisted arthroplasty devices that are the subject of this review are licensed by Health Canada. Robotic systems are active robots that mill bone according to information from a computer-assisted navigation system. The robotic-assisted arthroplasty devices that are the subject of this review are not currently licensed by Health Canada. The Cochrane and International Network of Agencies for Health Technology Assessment databases did not identify any health technology assessments on navigation or robotic-assisted hip or knee arthroplasty. The MEDLINE and EMBASE databases were searched for articles published between January 1, 1996 and November 30, 2003. This search produced 367 studies, of which 9 met the inclusion criteria. NAVIGATION-ASSISTED ARTHROPLASTY: Five studies were identified that examined navigation-assisted arthroplasty.A Level 1 evidence study from Germany found a statistically significant difference in alignment and angular deviation between navigation-assisted and free-hand total knee arthroplasty in favour of navigation-assisted surgery. However, the endpoints in this study were short-term. To date, the long-term effects (need for revision, implant longevity, pain, functional performance) are unknown.(1)A Level 2 evidence short-term study found that navigation-assisted total knee arthroplasty was significantly better than a non-navigated procedure for one of five postoperative measured angles.(2)A Level 2 evidence short-term study found no statistically significant difference in the variation of the abduction angle between navigation-assisted and conventional total hip arthroplasty.(3)Level 3 evidence observational studies of navigation-assisted total knee arthroplasty and unicompartmental knee arthroplasty have been conducted. Two studies reported that "the follow-up of the navigated prostheses is currently too short to know if clinical outcome or survival rates are improved. Longer follow-up is required to determine the respective advantages and disadvantages of both techniques."(4;5) ROBOTIC-ASSISTED ARTHROPLASTY: Four studies were identified that examined robotic-assisted arthroplasty.A Level 1 evidence study revealed that there was no statistically significant difference between functional hip scores at 24 months post implantation between patients who underwent robotic-assisted primary hip arthroplasty and those that were treated with manual implantation.(6)Robotic-assisted arthroplasty had advantages in terms of preoperative planning and the accuracy of the intraoperative procedure.(6)Patients who underwent robotic-assisted hip arthroplasty had a higher dislocation rate and more revisions.(6)Robotic-assisted arthroplasty may prove effective with certain prostheses (e.g., anatomic) because their use may result in less muscle detachment.(6)An observational study (Level 3 evidence) found that the incidence of severe embolic events during hip relocation was lower with robotic arthroplasty than with manual surgery.(7)An observational study (Level 3 evidence) found that there was no significant difference in gait analyses of patients who underwent robotic-assisted total hip arthroplasty using robotic surgery compared to patients who were treated with conventional cementless total hip arthroplasty.(8)An observational study (Level 3 evidence) compared outcomes of total knee arthroplasty between patients undergoing robotic surgery and patients who were historical controls. Brief, qualitative results suggested that there was much broader variation of angles after manual total knee arthroplasty compared to the robotic technique and that there was no difference in knee functional scores or implant position at the 3 and 6 month follow-up.(9).

Computer-Assisted Hip and Knee Arthroplasty. Navigation and Active Robotic Systems

PubMed Central

2004-01-01

Executive Summary Objective The Medical Advisory Secretariat undertook a review of the evidence on the effectiveness and cost-effectiveness of computer assisted hip and knee arthroplasty. The two computer assisted arthroplasty systems that are the topics of this review are (1) navigation and (2) robotic-assisted hip and knee arthroplasty. The Technology Computer-assisted arthroplasty consists of navigation and robotic systems. Surgical navigation is a visualization system that provides positional information about surgical tools or implants relative to a target bone on a computer display. Most of the navigation-assisted arthroplasty devices that are the subject of this review are licensed by Health Canada. Robotic systems are active robots that mill bone according to information from a computer-assisted navigation system. The robotic-assisted arthroplasty devices that are the subject of this review are not currently licensed by Health Canada. Review Strategy The Cochrane and International Network of Agencies for Health Technology Assessment databases did not identify any health technology assessments on navigation or robotic-assisted hip or knee arthroplasty. The MEDLINE and EMBASE databases were searched for articles published between January 1, 1996 and November 30, 2003. This search produced 367 studies, of which 9 met the inclusion criteria. Summary of Findings Navigation-Assisted Arthroplasty Five studies were identified that examined navigation-assisted arthroplasty. A Level 1 evidence study from Germany found a statistically significant difference in alignment and angular deviation between navigation-assisted and free-hand total knee arthroplasty in favour of navigation-assisted surgery. However, the endpoints in this study were short-term. To date, the long-term effects (need for revision, implant longevity, pain, functional performance) are unknown.(1) A Level 2 evidence short-term study found that navigation-assisted total knee arthroplasty was significantly better than a non-navigated procedure for one of five postoperative measured angles.(2) A Level 2 evidence short-term study found no statistically significant difference in the variation of the abduction angle between navigation-assisted and conventional total hip arthroplasty.(3) Level 3 evidence observational studies of navigation-assisted total knee arthroplasty and unicompartmental knee arthroplasty have been conducted. Two studies reported that “the follow-up of the navigated prostheses is currently too short to know if clinical outcome or survival rates are improved. Longer follow-up is required to determine the respective advantages and disadvantages of both techniques.”(4;5) Robotic-Assisted Arthroplasty Four studies were identified that examined robotic-assisted arthroplasty. A Level 1 evidence study revealed that there was no statistically significant difference between functional hip scores at 24 months post implantation between patients who underwent robotic-assisted primary hip arthroplasty and those that were treated with manual implantation.(6) Robotic-assisted arthroplasty had advantages in terms of preoperative planning and the accuracy of the intraoperative procedure.(6) Patients who underwent robotic-assisted hip arthroplasty had a higher dislocation rate and more revisions.(6) Robotic-assisted arthroplasty may prove effective with certain prostheses (e.g., anatomic) because their use may result in less muscle detachment.(6) An observational study (Level 3 evidence) found that the incidence of severe embolic events during hip relocation was lower with robotic arthroplasty than with manual surgery.(7) An observational study (Level 3 evidence) found that there was no significant difference in gait analyses of patients who underwent robotic-assisted total hip arthroplasty using robotic surgery compared to patients who were treated with conventional cementless total hip arthroplasty.(8) An observational study (Level 3 evidence) compared outcomes of total knee arthroplasty between patients undergoing robotic surgery and patients who were historical controls. Brief, qualitative results suggested that there was much broader variation of angles after manual total knee arthroplasty compared to the robotic technique and that there was no difference in knee functional scores or implant position at the 3 and 6 month follow-up.(9) PMID:23074452

Extracting Topological Relations Between Indoor Spaces from Point Clouds

NASA Astrophysics Data System (ADS)

Tran, H.; Khoshelham, K.; Kealy, A.; Díaz-Vilariño, L.

2017-09-01

3D models of indoor environments are essential for many application domains such as navigation guidance, emergency management and a range of indoor location-based services. The principal components defined in different BIM standards contain not only building elements, such as floors, walls and doors, but also navigable spaces and their topological relations, which are essential for path planning and navigation. We present an approach to automatically reconstruct topological relations between navigable spaces from point clouds. Three types of topological relations, namely containment, adjacency and connectivity of the spaces are modelled. The results of initial experiments demonstrate the potential of the method in supporting indoor navigation.

AiGERM: A logic programming front end for GERM

NASA Technical Reports Server (NTRS)

Hashim, Safaa H.

1990-01-01

AiGerm (Artificially Intelligent Graphical Entity Relation Modeler) is a relational data base query and programming language front end for MCC (Mission Control Center)/STP's (Space Test Program) Germ (Graphical Entity Relational Modeling) system. It is intended as an add-on component of the Germ system to be used for navigating very large networks of information. It can also function as an expert system shell for prototyping knowledge-based systems. AiGerm provides an interface between the programming language and Germ.

Social Network Structures of Breast Cancer Patients and the Contributing Role of Patient Navigators.

PubMed

Gunn, Christine M; Parker, Victoria A; Bak, Sharon M; Ko, Naomi; Nelson, Kerrie P; Battaglia, Tracy A

2017-08-01

Minority women in the U.S. continue to experience inferior breast cancer outcomes compared with white women, in part due to delays in care delivery. Emerging cancer care delivery models like patient navigation focus on social barriers, but evidence demonstrating how these models increase social capital is lacking. This pilot study describes the social networks of newly diagnosed breast cancer patients and explores the contributing role of patient navigators. Twenty-five women completed a one hour interview about their social networks related to cancer care support. Network metrics identified important structural attributes and influential individuals. Bivariate associations between network metrics, type of network, and whether the network included a navigator were measured. Secondary analyses explored associations between network structures and clinical outcomes. We identified three types of networks: kin-based, role and/or affect-based, or heterogeneous. Network metrics did not vary significantly by network type. There was a low prevalence of navigators included in the support networks (25%). Network density scores were significantly higher in those networks without a navigator. Network metrics were not predictive of clinical outcomes in multivariate models. Patient navigators were not frequently included in support networks, but provided distinctive types of support. If navigators can identify patients with poorly integrated (less dense) social networks, or who have unmet tangible support needs, the intensity of navigation services could be tailored. Services and systems that address gaps and variations in patient social networks should be explored for their potential to reduce cancer health disparities. This study used a new method to identify the breadth and strength of social support following a diagnosis of breast cancer, especially examining the role of patient navigators in providing support. While navigators were only included in one quarter of patient support networks, they did provide essential supports to some individuals. Health care providers and systems need to better understand the contributions of social supports both within and outside of health care to design and tailor interventions that seek to reduce health care disparities and improve cancer outcomes. © AlphaMed Press 2017.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

... Products, Components Thereof, and Related Software; Notice of Institution of Investigation; Institution of... importation of certain GPS navigation products, components thereof, and related software by reason of... importation of certain GPS navigation products, components thereof, and related software that infringe one or...

Novel robotic catheter manipulation system integrated with remote magnetic navigation for fully remote ablation of atrial tachyarrhythmias: a two-centre evaluation.

PubMed

Nölker, Georg; Gutleben, Klaus-Jürgen; Muntean, Bogdan; Vogt, Jürgen; Horstkotte, Dieter; Dabiri Abkenari, Lara; Akca, Ferdi; Szili-Torok, Tamas

2012-12-01

Studies have shown that remote magnetic navigation is safe and effective for ablation of atrial arrhythmias, although optimal outcomes often require frequent manual manipulation of a circular mapping catheter. The Vdrive robotic system ('Vdrive') was designed for remote navigation of circular mapping catheters to enable a fully remote procedure. This study details the first human clinical experience with remote circular catheter manipulation in the left atrium. This was a prospective, multi-centre, non-randomized consecutive case series that included patients presenting for catheter ablation of left atrial arrhythmias. Remote systems were used exclusively to manipulate both the circular mapping catheter and the ablation catheter. Patients were followed through hospital discharge. Ninety-four patients were included in the study, including 23 with paroxysmal atrial fibrillation (AF), 48 with persistent AF, and 15 suffering from atrial tachycardias. The population was predominately male (77%) with a mean age of 60.5 ± 11.7 years. The Vdrive was used for remote navigation between veins, creation of chamber maps, and gap identification with segmental isolation. The intended acute clinical endpoints were achieved in 100% of patients. Mean case time was 225.9 ± 70.5 min. Three patients (3.2%) crossed over to manual circular mapping catheter navigation. There were no adverse events related to the use of the remote manipulation system. The results of this study demonstrate that remote manipulation of a circular mapping catheter in the ablation of atrial arrhythmias is feasible and safe. Prospective randomized studies are needed to prove efficiency improvements over manual techniques.

Space-Based Information Services

NASA Astrophysics Data System (ADS)

Lee, C.

With useful data now beginning to flow from earth observation and navigation satellites, it is an active time for the development of space services - all types of satellites are now being put to work, not just Comsats. However derived products require a blend of innovative software design, low cost operational support and a real insight into the information needs of the customer. Science Systems is meeting this challenge through a series of on-going projects, three of which are summarised here (addressing navigation, communications and earth observation). By demonstrating a broad range of related disciplines; from monitoring and control to back-room billing; from data management to intelligent systems, Science Systems hopes to play a key role in this developing market.

33 CFR 149.415 - What are the requirements for a fire main system on a manned deepwater port?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What are the requirements for a fire main system on a manned deepwater port? 149.415 Section 149.415 Navigation and Navigable Waters... consensus standard, as that term is defined in 29 CFR 1910.2, for such systems and hardware, and comply with...

33 CFR 62.65 - Procedure for reporting defects and discrepancies.

Code of Federal Regulations, 2012 CFR

2012-07-01

... HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.65 Procedure for reporting defects and discrepancies. (a) Mariners should notify the nearest Coast Guard facility immediately of any observed aids to navigation defects or...

33 CFR 62.65 - Procedure for reporting defects and discrepancies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.65 Procedure for reporting defects and discrepancies. (a) Mariners should notify the nearest Coast Guard facility immediately of any observed aids to navigation defects or...

33 CFR 62.65 - Procedure for reporting defects and discrepancies.

Code of Federal Regulations, 2013 CFR

2013-07-01

... HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.65 Procedure for reporting defects and discrepancies. (a) Mariners should notify the nearest Coast Guard facility immediately of any observed aids to navigation defects or...

33 CFR 62.65 - Procedure for reporting defects and discrepancies.

Code of Federal Regulations, 2014 CFR

2014-07-01

... HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.65 Procedure for reporting defects and discrepancies. (a) Mariners should notify the nearest Coast Guard facility immediately of any observed aids to navigation defects or...

33 CFR 62.65 - Procedure for reporting defects and discrepancies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM Public Participation in the Aids to Navigation System § 62.65 Procedure for reporting defects and discrepancies. (a) Mariners should notify the nearest Coast Guard facility immediately of any observed aids to navigation defects or...

33 CFR 187.304 - What vessels must be titled?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false What vessels must be titled? 187.304 Section 187.304 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY VESSEL IDENTIFICATION SYSTEM Guidelines for State Vessel Titling Systems § 187.304...

33 CFR 187.304 - What vessels must be titled?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What vessels must be titled? 187.304 Section 187.304 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) BOATING SAFETY VESSEL IDENTIFICATION SYSTEM Guidelines for State Vessel Titling Systems § 187.304...

Collective navigation of complex networks: Participatory greedy routing.

PubMed

Kleineberg, Kaj-Kolja; Helbing, Dirk

2017-06-06

Many networks are used to transfer information or goods, in other words, they are navigated. The larger the network, the more difficult it is to navigate efficiently. Indeed, information routing in the Internet faces serious scalability problems due to its rapid growth, recently accelerated by the rise of the Internet of Things. Large networks like the Internet can be navigated efficiently if nodes, or agents, actively forward information based on hidden maps underlying these systems. However, in reality most agents will deny to forward messages, which has a cost, and navigation is impossible. Can we design appropriate incentives that lead to participation and global navigability? Here, we present an evolutionary game where agents share the value generated by successful delivery of information or goods. We show that global navigability can emerge, but its complete breakdown is possible as well. Furthermore, we show that the system tends to self-organize into local clusters of agents who participate in the navigation. This organizational principle can be exploited to favor the emergence of global navigability in the system.

Lidar Systems for Precision Navigation and Safe Landing on Planetary Bodies

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Pierrottet, Diego F.; Petway, Larry B.; Hines, Glenn D.; Roback, Vincent E.

2011-01-01

The ability of lidar technology to provide three-dimensional elevation maps of the terrain, high precision distance to the ground, and approach velocity can enable safe landing of robotic and manned vehicles with a high degree of precision. Currently, NASA is developing novel lidar sensors aimed at needs of future planetary landing missions. These lidar sensors are a 3-Dimensional Imaging Flash Lidar, a Doppler Lidar, and a Laser Altimeter. The Flash Lidar is capable of generating elevation maps of the terrain that indicate hazardous features such as rocks, craters, and steep slopes. The elevation maps collected during the approach phase of a landing vehicle, at about 1 km above the ground, can be used to determine the most suitable safe landing site. The Doppler Lidar provides highly accurate ground relative velocity and distance data allowing for precision navigation to the landing site. Our Doppler lidar utilizes three laser beams pointed to different directions to measure line of sight velocities and ranges to the ground from altitudes of over 2 km. Throughout the landing trajectory starting at altitudes of about 20 km, the Laser Altimeter can provide very accurate ground relative altitude measurements that are used to improve the vehicle position knowledge obtained from the vehicle navigation system. At altitudes from approximately 15 km to 10 km, either the Laser Altimeter or the Flash Lidar can be used to generate contour maps of the terrain, identifying known surface features such as craters, to perform Terrain relative Navigation thus further reducing the vehicle s relative position error. This paper describes the operational capabilities of each lidar sensor and provides a status of their development. Keywords: Laser Remote Sensing, Laser Radar, Doppler Lidar, Flash Lidar, 3-D Imaging, Laser Altimeter, Precession Landing, Hazard Detection

How Marginalized Young People Access, Engage With, and Navigate Health-Care Systems in the Digital Age: Systematic Review.

PubMed

Robards, Fiona; Kang, Melissa; Usherwood, Tim; Sanci, Lena

2018-04-01

This systematic review examines how marginalized young people access and engage with health services and navigate health-care systems in high-income countries. Medline, CINAHL, PsychInfo, The University of Sydney Library database, and Google Scholar were searched to identify qualitative and quantitative original research, published from 2006 to 2017, that focused on selected definitions of marginalized young people (12 to 24 years), their parents/carers, and/or health professionals working with these populations. A thematic synthesis was undertaken identifying themes across and between groups on barriers and/or facilitators to access, engagement, and/or navigation of health-care systems. Of 1,796 articles identified, 68 studies in the final selection focused on marginalized young people who were homeless (n = 20), living in rural areas (n = 14), of refugee background (n = 11), gender and/or sexuality diverse (n = 11), indigenous (n = 4), low income (n = 4), young offenders (n = 2), or living with a disability (n = 2). Studies were from the United States, Australia, Canada, United Kingdom, New Zealand, and Portugal, including 44 qualitative, 16 quantitative, and 8 mixed-method study types. Sample sizes ranged from 3 to 1,388. Eight themes were identified relating to ability to recognize and understand health issues; service knowledge and attitudes toward help seeking; structural barriers; professionals' knowledge, skills, attitudes; service environments and structures; ability to navigate the health system; youth participation; and technology opportunities. Marginalized young people experience barriers in addition to those common to all young people. Future studies should consider the role of technology in access, engagement, and health system navigation, and the impact of intersectionality between marginalized groups. Copyright © 2017 The Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Graphical overview and navigation of electronic health records in a prototyping environment using Google Earth and openEHR archetypes.

PubMed

Sundvall, Erik; Nyström, Mikael; Forss, Mattias; Chen, Rong; Petersson, Håkan; Ahlfeldt, Hans

2007-01-01

This paper describes selected earlier approaches to graphically relating events to each other and to time; some new combinations are also suggested. These are then combined into a unified prototyping environment for visualization and navigation of electronic health records. Google Earth (GE) is used for handling display and interaction of clinical information stored using openEHR data structures and 'archetypes'. The strength of the approach comes from GE's sophisticated handling of detail levels, from coarse overviews to fine-grained details that has been combined with linear, polar and region-based views of clinical events related to time. The system should be easy to learn since all the visualization styles can use the same navigation. The structured and multifaceted approach to handling time that is possible with archetyped openEHR data lends itself well to visualizing and integration with openEHR components is provided in the environment.

Flight Testing of Terrain-Relative Navigation and Large-Divert Guidance on a VTVL Rocket

NASA Technical Reports Server (NTRS)

Trawny, Nikolas; Benito, Joel; Tweddle, Brent; Bergh, Charles F.; Khanoyan, Garen; Vaughan, Geoffrey M.; Zheng, Jason X.; Villalpando, Carlos Y.; Cheng, Yang; Scharf, Daniel P.;

Neuroendovascular magnetic navigation: clinical experience in ten patients.

PubMed

Dabus, Guilherme; Gerstle, Ronald J; Cross, Dewitte T; Derdeyn, Colin P; Moran, Christopher J

2007-04-01

The magnetic navigation system consists of an externally generated magnetic field that is used to control and steer a magnetically tipped microguidewire. The goal of this study was to demonstrate that the use of the magnetic navigation system and its magnetic microguidewire is feasible and safe in all types of neuroendovascular procedures. A magnetic navigation system is an interventional workstation that combines a biplanar fluoroscopy system with a computer-controlled magnetic field generator to provide both visualization and control of a magnetically activated endovascular microguidewire. Ten consecutive patients underwent a variety of neuroendovascular procedures using the magnetic guidance system and magnetic microguidewire. All patients presented with a neurovascular disease that was suitable for endovascular treatment. Multiple different devices and embolic agents were used. Of the ten patients, three were male and seven female. Their mean age was 53.9 years. The predominant neurovascular condition was the presence of intracranial aneurysm (nine patients). One patient had a left mandibular arteriovenous malformation. All treatments were successfully performed on the magnetic navigation system suite. The magnetic navigation system and the magnetic microguidewire allowed safe and accurate endovascular navigation allowing placement of the microcatheters in the desired location. There were no neurological complications or death in our series. The use of the magnetic navigation system and the magnetic microguidewire in the endovascular treatment of patients with neurovascular diseases is feasible and safe.

Target contrast considerations in millimeter wave radiometry for airborne navigation

NASA Technical Reports Server (NTRS)

Mayer, A.

1971-01-01

Target signal requirements for aircraft navigation systems that use radiometric receivers which map thermally emitted power radiated by terrain or power radiated by ground-based beacons are discussed. For selected millimeter wavelength bands, microwaves suffer relatively little degradation by absorption or scattering on passage through the atmosphere, despite extreme weather variations. Interest centers on 8-millimeter waves because of component availability, portability (small size), high image resolution, and all-weather capability at this wavelength. The idea of radiometric airborne navigation is introduced. Elements of radiometry, terrain radiation, and atmospheric transmission characteristics are reviewed. Data pertaining to these elements at 8 mm wavelength are collected. Calculation of radiometric contrasts is discussed for some simple models of terrain targets.

Initial experience of intraoperative three-dimensional navigation for liver resection using real-time virtual sonography.

PubMed

Satou, Shouichi; Aoki, Taku; Kaneko, Junichi; Sakamoto, Yoshihiro; Hasegawa, Kiyoshi; Sugawara, Yasuhiko; Arai, Osamu; Mitake, Tsuyoshi; Miura, Koui; Kokudo, Norihiro

2014-02-01

Real-time virtual sonography is an innovative imaging technology that detects the spatial position of an ultrasound probe and immediately reconstructs a section of computed tomography (CT) and/or magnetic resonance in accordance with the ultrasound image, thereby allowing a real-time comparison of those modalities. A novel intraoperative navigation system for liver resection using real-time virtual sonography has been devised for the detection of tumors and navigation of the resection plane. Sixteen patients with hepatic malignancies (26 tumors in total) were involved in this study, and the system was used intraoperatively. The tumor size ranged 2 to 140 mm (23 mm in median). By the navigation system, operators could refer intraoperative ultrasound image displayed on the television monitor side-by-side with corresponding images of CT and/or magnetic resonance. In addition, the system overlaid preoperative simulation on the CT image and highlighted the extent of resection so as to navigate the resection plane. Because the system used electromagnetic power in the operation room, the feasibility and safety of the system was investigated as well as its validity. The system could be used uneventfully in each operation. All of the 26 tumors scheduled to be resected were detected by the navigation system. The weight of the resected specimen correlated with the preoperatively simulated volume (R = 0.995, P < .0001). The feasibility and safety of the navigation system were confirmed. The system should be helpful for intraoperative tumor detection and navigation of liver resection.

Development of water level regulation strategy for fish and wildlife, upper Mississippi River system

USGS Publications Warehouse

Lubinski, Kenneth S.; Carmody, G.; Wilcox, D.; Drazkowski, B.

1991-01-01

Water level regulation has been proposed as a tool for maintaining or enhancing fish and wildlife resources in navigation pools and associated flood plains of the Upper Mississippi River System. Research related to the development of water level management plans is being conducted under the Long Term Resource Monitoring Program. Research strategies include investigations of cause and effect relationships, spatial and temporal patterns of resource components, and alternative problem solutions. The principal hypothesis being tested states that water level fluctuations resulting from navigation dam operation create less than optimal conditions for the reproduction and growth of target aquatic macrophyte and fish species. Representative navigation pools have been selected to describe hydrologic, engineering, and legal constraints within which fish and wildlife objectives can be established. Spatial analyses are underway to predict the magnitude and location of habitat changes that will result from controlled changes in water elevation.

78 FR 73995 - Special Conditions: Cessna Model 680 Series Airplanes; Aircraft Electronic System Security...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-10

... critical systems and data networks. The network architecture is composed of several connected networks including the following: 1. Flight-Safety related control and navigation systems, 2. Operator business and... the individual sending the comment (or signing the comment for an association, business, labor union...

SU-F-P-42: “To Navigate, Or Not to Navigate: HDR BT in Recurrent Spine Lesions”

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

Voros, L; Cohen, G; Zaider, M

Purpose: We compare the accuracy of HDR catheter placement for paraspinal lesions using O-arm CBCT imaging combined with StealthStation navigation and traditional fluoroscopically guided catheter placement. Methods: CT and MRI scans were acquired pre-treatment to outline the lesions and design treatment plans (pre-plans) to meet dosimetric constrains. The pre-planned catheter trajectories were transferred into the StealthStation Navigation system prior to the surgery. The StealthStation is an infra red (IR) optical navigation system used for guidance of surgical instruments. An intraoperative CBCT scan (O-arm) was acquired with reference IR optical fiducials anchored onto the patient and registered with the preplan imagemore » study to guide surgical instruments in relation to the patients’ anatomy and to place the brachytherapy catheters along the pre-planned trajectories. The final treatment plan was generated based on a 2nd intraoperative CBCT scan reflecting achieved implant geometry. The 2nd CBCT was later registered with the initial CT scan to compare the preplanned dwell positions with actual dwell positions (catheter placements). Similar workflow was used in placement of 8 catheters (1 patient) without navigation, but under fluoroscopy guidance in an interventional radiology suite. Results: A total of 18 catheters (3 patients) were placed using navigation assisted surgery. Average displacement of 0.66 cm (STD=0.37cm) was observed between the pre-plan source positions and actual source positions in the 3 dimensional space. This translates into an average 0.38 cm positioning error in one direction including registration errors, digitization errors, and the surgeons ability to follow the planned trajectory. In comparison, average displacement of non-navigated catheters was 0.50 cm (STD=0.22cm). Conclusion: Spinal lesion HDR brachytherapy planning is a difficult task. Catheter placement has a direct impact on target coverage and dose to critical structures. While limited to a handful of patients, our experience shows navigation and fluoroscopy guided placement yield similar results.« less

Design, Development and Testing of the Miniature Autonomous Extravehicular Robotic Camera (Mini AERCam) Guidance, Navigation and Control System

NASA Technical Reports Server (NTRS)

Wagenknecht, J.; Fredrickson, S.; Manning, T.; Jones, B.

2003-01-01

Engineers at NASA Johnson Space Center have designed, developed, and tested a nanosatellite-class free-flyer intended for future external inspection and remote viewing of human spaceflight activities. The technology demonstration system, known as the Miniature Autonomous Extravehicular Robotic Camera (Mini AERCam), has been integrated into the approximate form and function of a flight system. The primary focus has been to develop a system capable of providing external views of the International Space Station. The Mini AERCam system is spherical-shaped and less than eight inches in diameter. It has a full suite of guidance, navigation, and control hardware and software, and is equipped with two digital video cameras and a high resolution still image camera. The vehicle is designed for either remotely piloted operations or supervised autonomous operations. Tests have been performed in both a six degree-of-freedom closed-loop orbital simulation and on an air-bearing table. The Mini AERCam system can also be used as a test platform for evaluating algorithms and relative navigation for autonomous proximity operations and docking around the Space Shuttle Orbiter or the ISS.

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

NASA Technical Reports Server (NTRS)

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

1983-01-01

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

Human Factors Considerations for Area Navigation Departure and Arrival Procedures

NASA Technical Reports Server (NTRS)

Barhydt, Richard; Adams, Catherine A.

2006-01-01

Area navigation (RNAV) procedures are being implemented in the United States and around the world as part of a transition to a performance-based navigation system. These procedures are providing significant benefits and have also caused some human factors issues to emerge. Under sponsorship from the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA) has undertaken a project to document RNAV-related human factors issues and propose areas for further consideration. The component focusing on RNAV Departure and Arrival Procedures involved discussions with expert users, a literature review, and a focused review of the NASA Aviation Safety Reporting System (ASRS) database. Issues were found to include aspects of air traffic control and airline procedures, aircraft systems, and procedure design. Major findings suggest the need for specific instrument procedure design guidelines that consider the effects of human performance. Ongoing industry and government activities to address air-ground communication terminology, design improvements, and chart-database commonality are strongly encouraged. A review of factors contributing to RNAV in-service errors would likely lead to improved system design and operational performance.

Interactive knowledge networks for interdisciplinary course navigation within Moodle.

PubMed

Scherl, Andre; Dethleffsen, Kathrin; Meyer, Michael

2012-12-01

Web-based hypermedia learning environments are widely used in modern education and seem particularly well suited for interdisciplinary learning. Previous work has identified guidance through these complex environments as a crucial problem of their acceptance and efficiency. We reasoned that map-based navigation might provide straightforward and effortless orientation. To achieve this, we developed a clickable and user-oriented concept map-based navigation plugin. This tool is implemented as an extension of Moodle, a widely used learning management system. It visualizes inner and interdisciplinary relations between learning objects and is generated dynamically depending on user set parameters and interactions. This plugin leaves the choice of navigation type to the user and supports direct guidance. Previously developed and evaluated face-to-face interdisciplinary learning materials bridging physiology and physics courses of a medical curriculum were integrated as learning objects, the relations of which were defined by metadata. Learning objects included text pages, self-assessments, videos, animations, and simulations. In a field study, we analyzed the effects of this learning environment on physiology and physics knowledge as well as the transfer ability of third-term medical students. Data were generated from pre- and posttest questionnaires and from tracking student navigation. Use of the hypermedia environment resulted in a significant increase of knowledge and transfer capability. Furthermore, the efficiency of learning was enhanced. We conclude that hypermedia environments based on Moodle and enriched by concept map-based navigation tools can significantly support interdisciplinary learning. Implementation of adaptivity may further strengthen this approach.

Determining Locations by Use of Networks of Passive Beacons

NASA Technical Reports Server (NTRS)

Okino, Clayton; Gray, Andrew; Jennings, Esther

2009-01-01

Networks of passive radio beacons spanning moderate-sized terrain areas have been proposed to aid navigation of small robotic aircraft that would be used to explore Saturn s moon Titan. Such networks could also be used on Earth to aid navigation of robotic aircraft, land vehicles, or vessels engaged in exploration or reconnaissance in situations or locations (e.g., underwater locations) in which Global Positioning System (GPS) signals are unreliable or unavailable. Prior to use, it would be necessary to pre-position the beacons at known locations that would be determined by use of one or more precise independent global navigation system(s). Thereafter, while navigating over the area spanned by a given network of passive beacons, an exploratory robot would use the beacons to determine its position precisely relative to the known beacon positions (see figure). If it were necessary for the robot to explore multiple, separated terrain areas spanned by different networks of beacons, the robot could use a long-haul, relatively coarse global navigation system for the lower-precision position determination needed during transit between such areas. The proposed method of precise determination of position of an exploratory robot relative to the positions of passive radio beacons is based partly on the principles of radar and partly on the principles of radio-frequency identification (RFID) tags. The robot would transmit radar-like signals that would be modified and reflected by the passive beacons. The distance to each beacon would be determined from the roundtrip propagation time and/or round-trip phase shift of the signal returning from that beacon. Signals returned from different beacons could be distinguished by means of their RFID characteristics. Alternatively or in addition, the antenna of each beacon could be designed to radiate in a unique pattern that could be identified by the navigation system. Also, alternatively or in addition, sets of identical beacons could be deployed in unique configurations such that the navigation system could identify their unique combinations of radio-frequency reflections as an alternative to leveraging the uniqueness of the RFID tags. The degree of dimensional accuracy would depend not only on the locations of the beacons but also on the number of beacon signals received, the number of samples of each signal, the motion of the robot, and the time intervals between samples. At one extreme, a single sample of the return signal from a single beacon could be used to determine the distance from that beacon and hence to determine that the robot is located somewhere on a sphere, the radius of which equals that distance and the center of which lies at the beacon. In a less extreme example, the three-dimensional position of the robot could be determined with fair precision from a single sample of the signal from each of three beacons. In intermediate cases, position estimates could be refined and/or position ambiguities could be resolved by use of supplementary readings of an altimeter and other instruments aboard the robot.

A Functional Description of a Digital Flight Test System for Navigation and Guidance Research in the Terminal Area

NASA Technical Reports Server (NTRS)

Hegarty, D. M.

1974-01-01

A guidance, navigation, and control system, the Simulated Shuttle Flight Test System (SS-FTS), when interfaced with existing aircraft systems, provides a research facility for studying concepts for landing the space shuttle orbiter and conventional jet aircraft. The SS-FTS, which includes a general-purpose computer, performs all computations for precisely following a prescribed approach trajectory while properly managing the vehicle energy to allow safe arrival at the runway and landing within prescribed dispersions. The system contains hardware and software provisions for navigation with several combinations of possible navigation aids that have been suggested for the shuttle. The SS-FTS can be reconfigured to study different guidance and navigation concepts by changing only the computer software, and adapted to receive different radio navigation information through minimum hardware changes. All control laws, logic, and mode interlocks reside solely in the computer software.

Applications of different design methodologies in navigation systems and development at JPL

NASA Technical Reports Server (NTRS)

Thurman, S. W.

1990-01-01

The NASA/JPL deep space navigation system consists of a complex array of measurement systems, data processing systems, and support facilities, with components located both on the ground and on-board interplanetary spacecraft. From its beginings nearly 30 years ago, this system has steadily evolved and grown to meet the demands for ever-increasing navigation accuracy placed on it by a succession of unmanned planetary missions. Principal characteristics of this system are its capabilities and great complexity. Three examples in the design and development of interplanetary space navigation systems are examined in order to make a brief assessment of the usefulness of three basic design theories, known as normative, rational, and heuristic. Evaluation of the examples indicates that a heuristic approach, coupled with rational-based mathematical and computational analysis methods, is used most often in problems such as orbit determination strategy development and mission navigation system design, while normative methods have seen only limited use is such applications as the development of large software systems and in the design of certain operational navigation subsystems.

Miniaturized GPS/MEMS IMU integrated board

NASA Technical Reports Server (NTRS)

Lin, Ching-Fang (Inventor)

2012-01-01

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.

Altair Navigation During Trans-Lunar Cruise, Lunar Orbit, Descent and Landing

NASA Technical Reports Server (NTRS)

Ely, Todd A.; Heyne, Martin; Riedel, Joseph E.

2010-01-01

The Altair lunar lander navigation system is driven by a set of requirements that not only specify a need to land within 100 m of a designated spot on the Moon, but also be capable of a safe return to an orbiting Orion capsule in the event of loss of Earth ground support. These requirements lead to the need for a robust and capable on-board navigation system that works in conjunction with an Earth ground navigation system that uses primarily ground-based radiometric tracking. The resulting system relies heavily on combining a multiplicity of data types including navigation state updates from the ground based navigation system, passive optical imaging from a gimbaled camera, a stable inertial measurement unit, and a capable radar altimeter and velocimeter. The focus of this paper is on navigation performance during the trans-lunar cruise, lunar orbit, and descent/landing mission phases with the goal of characterizing knowledge and delivery errors to key mission events, bound the statistical delta V costs for executing the mission, as well as the determine the landing dispersions due to navigation. This study examines the nominal performance that can be obtained using the current best estimate of the vehicle, sensor, and environment models. Performance of the system under a variety sensor outages and parametric trades is also examined.

Navigating oceans and cultures: Polynesian and European navigation systems in the late eighteenth century

NASA Astrophysics Data System (ADS)

Walker, M.

2012-05-01

Significant differences in the rotation of the celestial dome between the tropical and temperate zones did not stop the peoples of either the tropical Pacific or temperate Europe from using geocentric astronomy to guide exploration of the oceans. Although the differences in the night sky contributed to differences between the Pacific Island and European systems for navigation at sea, the two navigation systems exhibit substantial similarities. Both systems define positions on the surface of the Earth using two coordinates that vary at right angles to each other and use stars, and to a lesser extent the sun, to determine directions. This essay explores similarities and differences in the use of geocentric astronomy for navigation at sea by the peoples of Polynesia and Europe in the late eighteenth century. Captain Cook's orders to discover the unknown southern continent after observing the transit of Venus combined with differences in language and culture to obscure the deeper similarities between the navigation systems used by Cook and the Polynesians. Although it was a further 200 years before anthropologists studied Pacific navigation, collaborations in voyaging with communities in Oceania demonstrated the effectiveness of Pacific navigation systems, revived interest in traditional voyaging in island communities around the Pacific, and potentially open the way for further collaborations in other areas.

Demonstration of coherent Doppler lidar for navigation in GPS-denied environments

NASA Astrophysics Data System (ADS)

Amzajerdian, Farzin; Hines, Glenn D.; Pierrottet, Diego F.; Barnes, Bruce W.; Petway, Larry B.; Carson, John M.

2017-05-01

A coherent Doppler lidar has been developed to address NASA's need for a high-performance, compact, and cost-effective velocity and altitude sensor onboard its landing vehicles. Future robotic and manned missions to solar system bodies require precise ground-relative velocity vector and altitude data to execute complex descent maneuvers and safe, soft landing at a pre-designated site. This lidar sensor, referred to as a Navigation Doppler Lidar (NDL), meets the required performance of the landing missions while complying with vehicle size, mass, and power constraints. Operating from up to four kilometers altitude, the NDL obtains velocity and range precision measurements reaching 2 cm/sec and 2 meters, respectively, dominated by the vehicle motion. Terrestrial aerial vehicles will also benefit from NDL data products as enhancement or replacement to GPS systems when GPS is unavailable or redundancy is needed. The NDL offers a viable option to aircraft navigation in areas where the GPS signal can be blocked or jammed by intentional or unintentional interference. The NDL transmits three laser beams at different pointing angles toward the ground to measure range and velocity along each beam using a frequency modulated continuous wave (FMCW) technique. The three line-of-sight measurements are then combined in order to determine the three components of the vehicle velocity vector and its altitude relative to the ground. This paper describes the performance and capabilities that the NDL demonstrated through extensive ground tests, helicopter flight tests, and onboard an autonomous rocket-powered test vehicle while operating in closedloop with a guidance, navigation, and control (GN and C) system.

77 FR 16562 - Certain Navigation Products, Components Thereof, and Related Software; Determination Not To...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-810] Certain Navigation Products, Components Thereof, and Related Software; Determination Not To Review an Initial Determination Granting a... United States after importation of certain navigation products, components thereof, and related software...

Combined CT-based and image-free navigation systems in TKA reduces postoperative outliers of rotational alignment of the tibial component.

PubMed

Mitsuhashi, Shota; Akamatsu, Yasushi; Kobayashi, Hideo; Kusayama, Yoshihiro; Kumagai, Ken; Saito, Tomoyuki

2018-02-01

Rotational malpositioning of the tibial component can lead to poor functional outcome in TKA. Although various surgical techniques have been proposed, precise rotational placement of the tibial component was difficult to accomplish even with the use of a navigation system. The purpose of this study is to assess whether combined CT-based and image-free navigation systems replicate accurately the rotational alignment of tibial component that was preoperatively planned on CT, compared with the conventional method. We compared the number of outliers for rotational alignment of the tibial component using combined CT-based and image-free navigation systems (navigated group) with those of conventional method (conventional group). Seventy-two TKAs were performed between May 2012 and December 2014. In the navigated group, the anteroposterior axis was prepared using CT-based navigation system and the tibial component was positioned under control of the navigation. In the conventional group, the tibial component was placed with reference to the Akagi line that was determined visually. Fisher's exact probability test was performed to evaluate the results. There was a significant difference between the two groups with regard to the number of outliers: 3 outliers in the navigated group compared with 12 outliers in the conventional group (P < 0.01). We concluded that combined CT-based and image-free navigation systems decreased the number of rotational outliers of tibial component, and was helpful for the replication of the accurate rotational alignment of the tibial component that was preoperatively planned.

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

NASA Technical Reports Server (NTRS)

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

1993-01-01

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

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

NASA Technical Reports Server (NTRS)

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

1991-01-01

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

Autonomous GPS/INS navigation experiment for Space Transfer Vehicle

NASA Astrophysics Data System (ADS)

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

1993-07-01

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

Olfaction Contributes to Pelagic Navigation in a Coastal Shark.

PubMed

Nosal, Andrew P; Chao, Yi; Farrara, John D; Chai, Fei; Hastings, Philip A

2016-01-01

How animals navigate the constantly moving and visually uniform pelagic realm, often along straight paths between distant sites, is an enduring mystery. The mechanisms enabling pelagic navigation in cartilaginous fishes are particularly understudied. We used shoreward navigation by leopard sharks (Triakis semifasciata) as a model system to test whether olfaction contributes to pelagic navigation. Leopard sharks were captured alongshore, transported 9 km offshore, released, and acoustically tracked for approximately 4 h each until the transmitter released. Eleven sharks were rendered anosmic (nares occluded with cotton wool soaked in petroleum jelly); fifteen were sham controls. Mean swimming depth was 28.7 m. On average, tracks of control sharks ended 62.6% closer to shore, following relatively straight paths that were significantly directed over spatial scales exceeding 1600 m. In contrast, tracks of anosmic sharks ended 37.2% closer to shore, following significantly more tortuous paths that approximated correlated random walks. These results held after swimming paths were adjusted for current drift. This is the first study to demonstrate experimentally that olfaction contributes to pelagic navigation in sharks, likely mediated by chemical gradients as has been hypothesized for birds. Given the similarities between the fluid three-dimensional chemical atmosphere and ocean, further research comparing swimming and flying animals may lead to a unifying paradigm explaining their extraordinary navigational abilities.

Navigation lymphatic supermicrosurgery for the treatment of cancer-related peripheral lymphedema.

PubMed

Yamamoto, Takumi; Yamamoto, Nana; Numahata, Takao; Yokoyama, Ai; Tashiro, Kensuke; Yoshimatsu, Hidehiko; Narushima, Mitsunaga; Koshima, Isao

2014-02-01

Lymphatic supermicrosurgery is becoming the treatment of choice for refractory lymphedema. Detection and anastomosis of functional lymphatic vessels are important for lymphatic supermicrosurgery. Navigation lymphatic supermicrosurgery was performed using an operating microscope equipped with an integrated near-infrared illumination system (OPMI Pentero Infrared 800; Carl Zeiss, Oberkochen, Germany). Eight patients with extremity lymphedema who underwent navigation lymphatic supermicrosurgery were evaluated. A total of 21 lymphaticovenular anastomoses were performed on 8 limbs through 14 skin incisions. Lymphatic vessels were enhanced by intraoperative microscopic indocyanine green (ICG) lymphography in 12 of the 14 skin incisions, which resulted in early dissection of lymphatic vessels. All anastomoses showed good anastomosis patency after completion of anastomoses. Postoperative extremity lymphedema index decreased in all limbs. Navigation lymphatic supermicrosurgery, in which lymphatic vessels are visualized with intraoperative microscopic ICG lymphography, allows a lymphatic supermicrosurgeon to find and dissect lymphatic vessels earlier and facilitates successful performance of lymphaticovenular anastomosis.

33 CFR 66.10-1 - General.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS..., the Uniform State Waterway Marking System's (USWMS) aids to navigation provisions for marking channels... waters for private aids to navigation and in those internal waters that are non-navigable waters of the U...

33 CFR 66.01-1 - Basic provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 66.01-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-1 Basic provisions. (a) The Uniform State Waterway Marking System's (USWMS) aids to navigation provisions for marking...

33 CFR 66.10-1 - General.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS..., the Uniform State Waterway Marking System's (USWMS) aids to navigation provisions for marking channels... waters for private aids to navigation and in those internal waters that are non-navigable waters of the U...

33 CFR 66.01-1 - Basic provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 66.01-1 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-1 Basic provisions. (a) The Uniform State Waterway Marking System's (USWMS) aids to navigation provisions for marking...

A novel technique for tailoring frontal osteoplastic flaps using the ENT magnetic navigation system.

PubMed

Volpi, Luca; Pistochini, Andrea; Bignami, Maurizio; Meloni, Francesco; Turri Zanoni, Mario; Castelnuovo, Paolo

2012-06-01

The ENT magnetic navigation system is potentially useful and offers the most accurate technique for harvesting frontal osteoplastic flaps. It represents a valid tool in the wide range of instruments available to rhinologists. Precise delineation of the boundaries of the frontal sinus is a crucial step when harvesting a frontal osteoplastic flap. We present a novel technique using the ENT magnetic navigation system. Nineteen patients affected by different pathologies involving the frontal sinus underwent an osteoplastic flap procedure using the ENT magnetic navigation system between January 2009 and April 2011. The ENT magnetic navigation system was found to be a safe and accurate tool for delineating the frontal sinus boundaries. No intraoperative complications occurred during the osteoplastic procedures.

Preliminary Design of Nano Satellite for Regional Navigation System

NASA Astrophysics Data System (ADS)

Fathurrohim, L.; Poetro, R. E.; Kurniadi, B.; Fadillah, P. A.; Iqbal, M.

2018-04-01

A Low cost Regional Navigation Satellite System employing constellation of nano satellites has been proposed for Indonesian coverage. The constellation of Low Earth Orbit nano satellites off course will not be able to give better position fixed to the GPS. However, the design of navigation system has much lower in cost compare to the current navigation system. This paper tells about preliminary design of the proposed regional navigation satellite system. The results of our satellite design has 3 kg on its weight, 10 W on power requirement at the peak condition, and 2.7 years of lifetime. Payload communication of the satellite will use UHF and TT&C communication will use VHF. Total area of solar panel will be 0.11 m2.

Design of a web portal for interdisciplinary image retrieval from multiple online image resources.

PubMed

Kammerer, F J; Frankewitsch, T; Prokosch, H-U

2009-01-01

Images play an important role in medicine. Finding the desired images within the multitude of online image databases is a time-consuming and frustrating process. Existing websites do not meet all the requirements for an ideal learning environment for medical students. This work intends to establish a new web portal providing a centralized access point to a selected number of online image databases. A back-end system locates images on given websites and extracts relevant metadata. The images are indexed using UMLS and the MetaMap system provided by the US National Library of Medicine. Specially developed functions allow to create individual navigation structures. The front-end system suits the specific needs of medical students. A navigation structure consisting of several medical fields, university curricula and the ICD-10 was created. The images may be accessed via the given navigation structure or using different search functions. Cross-references are provided by the semantic relations of the UMLS. Over 25,000 images were identified and indexed. A pilot evaluation among medical students showed good first results concerning the acceptance of the developed navigation structures and search features. The integration of the images from different sources into the UMLS semantic network offers a quick and an easy-to-use learning environment.

33 CFR 66.10-35 - Navigation lights.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navigation lights. 66.10-35... NAVIGATION PRIVATE AIDS TO NAVIGATION Uniform State Waterway Marking System § 66.10-35 Navigation lights. A red light shall only be used on a solid colored red buoy. A green light shall only be used on a solid...

33 CFR 66.10-35 - Navigation lights.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Navigation lights. 66.10-35... NAVIGATION PRIVATE AIDS TO NAVIGATION Uniform State Waterway Marking System § 66.10-35 Navigation lights. A red light shall only be used on a solid colored red buoy. A green light shall only be used on a solid...

33 CFR 66.10-35 - Navigation lights.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Navigation lights. 66.10-35... NAVIGATION PRIVATE AIDS TO NAVIGATION Uniform State Waterway Marking System § 66.10-35 Navigation lights. A red light shall only be used on a solid colored red buoy. A green light shall only be used on a solid...

33 CFR 66.10-35 - Navigation lights.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Navigation lights. 66.10-35... NAVIGATION PRIVATE AIDS TO NAVIGATION Uniform State Waterway Marking System § 66.10-35 Navigation lights. A red light shall only be used on a solid colored red buoy. A green light shall only be used on a solid...

33 CFR 66.10-35 - Navigation lights.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Navigation lights. 66.10-35... NAVIGATION PRIVATE AIDS TO NAVIGATION Uniform State Waterway Marking System § 66.10-35 Navigation lights. A red light shall only be used on a solid colored red buoy. A green light shall only be used on a solid...

Multi-Sensor Testing for Automated Rendezvous and Docking Sensor Testing at the Flight Robotics Laboratory

NASA Technical Reports Server (NTRS)

Brewster, L.; Johnston, A.; Howard, R.; Mitchell, J.; Cryan, S.

2007-01-01

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as AR&D). The crewed missions may also perform rendezvous and docking operations and may require different levels of automation and/or autonomy, and must provide the crew with relative navigation information for manual piloting. The capabilities of the RPOD sensors are critical to the success of the Exploration Program. NASA has the responsibility to determine whether the Crew Exploration Vehicle (CEV) contractor proposed relative navigation sensor suite will meet the requirements. The relatively low technology readiness level of AR&D relative navigation sensors has been carried as one of the CEV Project's top risks. The AR&D Sensor Technology Project seeks to reduce the risk by the testing and analysis of selected relative navigation sensor technologies through hardware-in-the-loop testing and simulation. These activities will provide the CEV Project information to assess the relative navigation sensors maturity as well as demonstrate test methods and capabilities. The first year of this project focused on a series of"pathfinder" testing tasks to develop the test plans, test facility requirements, trajectories, math model architecture, simulation platform, and processes that will be used to evaluate the Contractor-proposed sensors. Four candidate sensors were used in the first phase of the testing. The second phase of testing used four sensors simultaneously: two Marshall Space Flight Center (MSFC) Advanced Video Guidance Sensors (AVGS), a laser-based video sensor that uses retroreflectors attached to the target vehicle, and two commercial laser range finders. The multi-sensor testing was conducted at MSFC's Flight Robotics Laboratory (FRL) using the FRL's 6-DOF gantry system, called the Dynamic Overhead Target System (DOTS). The target vehicle for "docking" in the laboratory was a mockup that was representative of the proposed CEV docking system, with added retroreflectors for the AVGS. The multi-sensor test configuration used 35 open-loop test trajectories covering three major objectives: (1) sensor characterization trajectories designed to test a wide range of performance parameters; (2) CEV-specific trajectories designed to test performance during CEV-like approach and departure profiles; and (3) sensor characterization tests designed for evaluating sensor performance under more extreme conditions as might be induced during a spacecraft failure or during contingency situations. This paper describes the test development, test facility, test preparations, test execution, and test results of the multi-sensor series of trajectories.

National Airspace System : persistent problems in FAA's new navigation system highlight need for periodic reevaluation

DOT National Transportation Integrated Search

2000-06-01

Currently, the Federal Aviation Administration (FAA) relies principally on a ground-based navigation system that uses various types of equipment to assist pilots in navigating their assigned routes and to provide them with guidance for landing their ...

77 FR 13350 - Certain Automotive GPS Navigation Systems, Components Thereof, and Products Containing Same...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-06

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-814] Certain Automotive GPS Navigation Systems, Components Thereof, and Products Containing Same; Determination Not To Review Initial... importation of certain automotive GPS navigation systems, components thereof, and products containing the same...

Design, development and evaluation of a compact telerobotic catheter navigation system.

PubMed

Tavallaei, Mohammad Ali; Gelman, Daniel; Lavdas, Michael Konstantine; Skanes, Allan C; Jones, Douglas L; Bax, Jeffrey S; Drangova, Maria

2016-09-01

Remote catheter navigation systems protect interventionalists from scattered ionizing radiation. However, these systems typically require specialized catheters and extensive operator training. A new compact and sterilizable telerobotic system is described, which allows remote navigation of conventional tip-steerable catheters, with three degrees of freedom, using an interface that takes advantage of the interventionalist's existing dexterity skills. The performance of the system is evaluated ex vivo and in vivo for remote catheter navigation and ablation delivery. The system has absolute errors of 0.1 ± 0.1 mm and 7 ± 6° over 100 mm of axial motion and 360° of catheter rotation, respectively. In vivo experiments proved the safety of the proposed telerobotic system and demonstrated the feasibility of remote navigation and delivery of ablation. The proposed telerobotic system allows the interventionalist to use conventional steerable catheters; while maintaining a safe distance from the radiation source, he/she can remotely navigate the catheter and deliver ablation lesions. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Autonomous formation flying based on GPS — PRISMA flight results

NASA Astrophysics Data System (ADS)

D'Amico, Simone; Ardaens, Jean-Sebastien; De Florio, Sergio

2013-01-01

This paper presents flight results from the early harvest of the Spaceborne Autonomous Formation Flying Experiment (SAFE) conducted in the frame of the Swedish PRISMA technology demonstration mission. SAFE represents one of the first demonstrations in low Earth orbit of an advanced guidance, navigation and control system for dual-spacecraft formations. Innovative techniques based on differential GPS-based navigation and relative orbital elements control are validated and tuned in orbit to fulfill the typical requirements of future distributed scientific instruments for remote sensing.

Survey of computer vision technology for UVA navigation

NASA Astrophysics Data System (ADS)

Xie, Bo; Fan, Xiang; Li, Sijian

2017-11-01

Navigation based on computer version technology, which has the characteristics of strong independence, high precision and is not susceptible to electrical interference, has attracted more and more attention in the filed of UAV navigation research. Early navigation project based on computer version technology mainly applied to autonomous ground robot. In recent years, the visual navigation system is widely applied to unmanned machine, deep space detector and underwater robot. That further stimulate the research of integrated navigation algorithm based on computer version technology. In China, with many types of UAV development and two lunar exploration, the three phase of the project started, there has been significant progress in the study of visual navigation. The paper expounds the development of navigation based on computer version technology in the filed of UAV navigation research and draw a conclusion that visual navigation is mainly applied to three aspects as follows.(1) Acquisition of UAV navigation parameters. The parameters, including UAV attitude, position and velocity information could be got according to the relationship between the images from sensors and carrier's attitude, the relationship between instant matching images and the reference images and the relationship between carrier's velocity and characteristics of sequential images.(2) Autonomous obstacle avoidance. There are many ways to achieve obstacle avoidance in UAV navigation. The methods based on computer version technology ,including feature matching, template matching, image frames and so on, are mainly introduced. (3) The target tracking, positioning. Using the obtained images, UAV position is calculated by using optical flow method, MeanShift algorithm, CamShift algorithm, Kalman filtering and particle filter algotithm. The paper expounds three kinds of mainstream visual system. (1) High speed visual system. It uses parallel structure, with which image detection and processing are carried out at high speed. The system is applied to rapid response system. (2) The visual system of distributed network. There are several discrete image data acquisition sensor in different locations, which transmit image data to the node processor to increase the sampling rate. (3) The visual system combined with observer. The system combines image sensors with the external observers to make up for lack of visual equipment. To some degree, these systems overcome lacks of the early visual system, including low frequency, low processing efficiency and strong noise. In the end, the difficulties of navigation based on computer version technology in practical application are briefly discussed. (1) Due to the huge workload of image operation , the real-time performance of the system is poor. (2) Due to the large environmental impact , the anti-interference ability of the system is poor.(3) Due to the ability to work in a particular environment, the system has poor adaptability.

A Leapfrog Navigation System

NASA Astrophysics Data System (ADS)

Opshaug, Guttorm Ringstad

There are times and places where conventional navigation systems, such as the Global Positioning System (GPS), are unavailable due to anything from temporary signal occultations to lack of navigation system infrastructure altogether. The goal of the Leapfrog Navigation System (LNS) is to provide localized positioning services for such cases. The concept behind leapfrog navigation is to advance a group of navigation units teamwise into an area of interest. In a practical 2-D case, leapfrogging assumes known initial positions of at least two currently stationary navigation units. Two or more mobile units can then start to advance into the area of interest. The positions of the mobiles are constantly being calculated based on cross-range distance measurements to the stationary units, as well as cross-ranges among the mobiles themselves. At some point the mobile units stop, and the stationary units are released to move. This second team of units (now mobile) can then overtake the first team (now stationary) and travel even further towards the common goal of the group. Since there always is one stationary team, the position of any unit can be referenced back to the initial positions. Thus, LNS provides absolute positioning. I developed navigation algorithms needed to solve leapfrog positions based on cross-range measurements. I used statistical tools to predict how position errors would grow as a function of navigation unit geometry, cross-range measurement accuracy and previous position errors. Using this knowledge I predicted that a 4-unit Leapfrog Navigation System using 100 m baselines and 200 m leap distances could travel almost 15 km before accumulating absolute position errors of 10 m (1sigma). Finally, I built a prototype leapfrog navigation system using 4 GPS transceiver ranging units. I placed the 4 units in the vertices a 10m x 10m square, and leapfrogged the group 20 meters forwards, and then back again (40 m total travel). Average horizontal RMS position errors never exceeded 16 cm during these field tests.

In-motion initial alignment and positioning with INS/CNS/ODO integrated navigation system for lunar rovers

NASA Astrophysics Data System (ADS)

Lu, Jiazhen; Lei, Chaohua; Yang, Yanqiang; Liu, Ming

2017-06-01

Many countries have been paying great attention to space exploration, especially about the Moon and the Mars. Autonomous and high-accuracy navigation systems are needed for probers and rovers to accomplish missions. Inertial navigation system (INS)/celestial navigation system (CNS) based navigation system has been used widely on the lunar rovers. Initialization is a particularly important step for navigation. This paper presents an in-motion alignment and positioning method for lunar rovers by INS/CNS/odometer integrated navigation. The method can estimate not only the position and attitude errors, but also the biases of the accelerometers and gyros using the standard Kalman filter. The differences between the platform star azimuth, elevation angles and the computed star azimuth, elevation angles, and the difference between the velocity measured by odometer and the velocity measured by inertial sensors are taken as measurements. The semi-physical experiments are implemented to demonstrate that the position error can reduce to 10 m and attitude error is within 2″ during 5 min. The experiment results prove that it is an effective and attractive initialization approach for lunar rovers.

33 CFR 66.01-10 - Characteristics.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 66.01-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-10... States Aids to Navigation System set forth in subpart B of part 62 of this subchapter. [USCG-2000-7466...

33 CFR 66.10-1 - General.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS... Marking System's (USWMS) aids to navigation provisions for marking channels and obstructions (see § 66.10... private aids to navigation and in those internal waters that are non-navigable waters of the U.S. All...

33 CFR 66.10-1 - General.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS... Marking System's (USWMS) aids to navigation provisions for marking channels and obstructions (see § 66.10... private aids to navigation and in those internal waters that are non-navigable waters of the U.S. All...

33 CFR 66.01-10 - Characteristics.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 66.01-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-10... States Aids to Navigation System set forth in subpart B of part 62 of this subchapter. [USCG-2000-7466...

33 CFR 66.01-10 - Characteristics.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 66.01-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-10... States Aids to Navigation System set forth in subpart B of part 62 of this subchapter. [USCG-2000-7466...

33 CFR 66.01-10 - Characteristics.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 66.01-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-10... States Aids to Navigation System set forth in subpart B of part 62 of this subchapter. [USCG-2000-7466...

33 CFR 66.10-1 - General.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS... Marking System's (USWMS) aids to navigation provisions for marking channels and obstructions (see § 66.10... private aids to navigation and in those internal waters that are non-navigable waters of the U.S. All...

33 CFR 66.01-10 - Characteristics.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 66.01-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-10... States Aids to Navigation System set forth in subpart B of part 62 of this subchapter. [USCG-2000-7466...

Performance analysis of device-level SINS/ACFSS deeply integrated navigation method

NASA Astrophysics Data System (ADS)

Zhang, Hao; Qin, Shiqiao; Wang, Xingshu; Jiang, Guangwen; Tan, Wenfeng

2016-10-01

The Strap-Down Inertial Navigation System (SINS) is a widely used navigation system. The combination of SINS and the Celestial Navigation System (CNS) is one of the popular measures to constitute the integrated navigation system. A Star Sensor (SS) is used as a precise attitude determination device in CNS. To solve the problem that the star image obtained by SS under dynamic conditions is motion-blurred, the Attitude Correlated Frames (ACF) is presented and the star sensor which works based on ACF approach is named ACFSS. Depending on the ACF approach, a novel device-level SINS/ACFSS deeply integrated navigation method is proposed in this paper. Feedback to the ACF process from the error of the gyro is one of the typical characters of the SINS/CNS deeply integrated navigation method. Herein, simulation results have verified its validity and efficiency in improving the accuracy of gyro and it can be proved that this method is feasible in theory.

An excellent navigation system and experience in craniomaxillofacial navigation surgery: a double-center study

PubMed Central

Dai, Jiewen; Wu, Jinyang; Wang, Xudong; Yang, Xudong; Wu, Yunong; Xu, Bing; Shi, Jun; Yu, Hongbo; Cai, Min; Zhang, Wenbin; Zhang, Lei; Sun, Hao; Shen, Guofang; Zhang, Shilei

2016-01-01

Numerous problems regarding craniomaxillofacial navigation surgery are not well understood. In this study, we performed a double-center clinical study to quantitatively evaluate the characteristics of our navigation system and experience in craniomaxillofacial navigation surgery. Fifty-six patients with craniomaxillofacial disease were included and randomly divided into experimental (using our AccuNavi-A system) and control (using Strker system) groups to compare the surgical effects. The results revealed that the average pre-operative planning time was 32.32 mins vs 29.74 mins between the experimental and control group, respectively (p > 0.05). The average operative time was 295.61 mins vs 233.56 mins (p > 0.05). The point registration orientation accuracy was 0.83 mm vs 0.92 mm. The maximal average preoperative navigation orientation accuracy was 1.03 mm vs 1.17 mm. The maximal average persistent navigation orientation accuracy was 1.15 mm vs 0.09 mm. The maximal average navigation orientation accuracy after registration recovery was 1.15 mm vs 1.39 mm between the experimental and control group. All patients healed, and their function and profile improved. These findings demonstrate that although surgeons should consider the patients’ time and monetary costs, our qualified navigation surgery system and experience could offer an accurate guide during a variety of craniomaxillofacial surgeries. PMID:27305855

Investigation on navigation patterns of inertial/celestial integrated systems

NASA Astrophysics Data System (ADS)

Luo, Dacheng; Liu, Yan; Liu, Zhiguo; Jiao, Wei; Wang, Qiuyan

2014-11-01

It is known that Strapdown Inertial Navigation System (SINS), Global Navigation Satellite System (GNSS) and Celestial Navigation System (CNS) can complement each other's advantages. The SINS/CNS integrated system, which has the characteristics of strong autonomy, high accuracy and good anti-jamming, is widely used in military and civilian applications. Similar to SINS/GNSS integrated system, the SINS/CNS integrated system can also be divided into three kinds according to the difference of integrating depth, i.e., loosely coupled pattern, tightly coupled pattern and deeply coupled pattern. In this paper, the principle and characteristics of each pattern of SINS/CNS system are analyzed. Based on the comparison of these patterns, a novel deeply coupled SINS/CNS integrated navigation scheme is proposed. The innovation of this scheme is that a new star pattern matching method aided by SINS information is put forward. Thus the complementary features of these two subsystems are reflected.

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

NASA Astrophysics Data System (ADS)

Belyaev, E. N.

2017-10-01

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

Vdrive Evaluation of Remote Steering and Testing in Lasso Electrophysiology Procedures Study: The VERSATILE Study in Atrial Fibrillation Ablation.

PubMed

Nölker, Georg; Schwagten, Bruno; Deville, J Brian; Burkhardt, J David; Horton, Rodney P; Sha, Qun; Tomassoni, Gery

2016-03-01

Circular mapping catheters (CMC) are an essential tool in most atrial fibrillation ablation procedures. The Vdrive™ with V-Loop™ system enables a physician to remotely manipulate a CMC during electrophysiology studies. Our aim was to compare the clinical performance of the system to conventional CMC navigation according to efficiency and safety endpoints. A total of 120 patients scheduled to undergo a CMC study followed by pulmonary vein isolation (PVI) were included. Treatment allocation was randomized 2:1, remote navigation:manual navigation. The primary effectiveness endpoint was assessed based on both successful navigation to the targeted pulmonary vein (PV) and successful recording of PV electrograms. All PVs were treated independently within and between patients. The primary safety endpoint was assessed based on the occurrence of major adverse events (MAEs) through seven days after the study procedure. Primary effectiveness endpoints were achieved in 295/302 PVs in the Vdrive arm (97.7%) and 167/167 PVs in the manual arm (100%). Effectiveness analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0405; δ = -0.05) per the Cochran-Mantel-Haenszel test adjusted for PV correlation. Five MAEs related to the ablation procedure occurred (three in the Vdrive arm-3.9%; two in the manual arm-2.33%). No device-related MAEs were observed; safety analysis indicates Vdrive non-inferiority (pnon-inferiority = 0.0441; δ = 0.07) per the normal Z test. Remote navigation of a CMC is equivalent to manual in PVI in terms of safety and effectiveness. This allows for single-operator procedures in conjunction with a magnetically guided ablation catheter. © 2016 Wiley Periodicals, Inc.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-22

... INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-783] Certain GPS Navigation Products, Components Thereof, and Related Software; Termination of Investigation on the Basis of Settlement AGENCY: U.S... GPS navigation products, components thereof, and related software, by reason of the infringement of...

Lidar-Based Navigation Algorithm for Safe Lunar Landing

NASA Technical Reports Server (NTRS)

Myers, David M.; Johnson, Andrew E.; Werner, Robert A.

2011-01-01

The purpose of Hazard Relative Navigation (HRN) is to provide measurements to the Navigation Filter so that it can limit errors on the position estimate after hazards have been detected. The hazards are detected by processing a hazard digital elevation map (HDEM). The HRN process takes lidar images as the spacecraft descends to the surface and matches these to the HDEM to compute relative position measurements. Since the HDEM has the hazards embedded in it, the position measurements are relative to the hazards, hence the name Hazard Relative Navigation.

33 CFR 169.125 - What classes of ships are required to make reports?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What classes of ships are required to make reports? 169.125 Section 169.125 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Establishment of Two Mandatory Ship Reporting Systems for the...

33 CFR 169.130 - When are ships required to make reports?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false When are ships required to make reports? 169.130 Section 169.130 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Establishment of Two Mandatory Ship Reporting Systems for the Protection of...

TDRSS Onboard Navigation System (TONS) experiment for the Explorer Platform (EP)

NASA Astrophysics Data System (ADS)

Gramling, C. J.; Hornstein, R. S.; Long, A. C.; Samii, M. V.; Elrod, B. D.

A TDRSS Onboard Navigation System (TONS) is currently being developed by NASA to provide a high-accuracy autonomous spacecraft navigation capability for users of TDRSS and its successor, the Advanced TDRSS. A TONS experiment will be performed in conjunction with the Explorer Platform (EP)/EUV Explorer mission to flight-qualify TONS Block I. This paper presents an overview of TDRSS on-board navigation goals and plans and the technical objectives of the TONS experiment. The operations concept of the experiment is described, including the characteristics of the ultrastable oscillator, the Doppler extractor, the signal-acquisition process, the TONS ground-support system, and the navigation flight software. A description of the on-board navigation algorithms and the rationale for their selection is also presented.

Analysis of key technologies in geomagnetic navigation

NASA Astrophysics Data System (ADS)

Zhang, Xiaoming; Zhao, Yan

2008-10-01

Because of the costly price and the error accumulation of high precise Inertial Navigation Systems (INS) and the vulnerability of Global Navigation Satellite Systems (GNSS), the geomagnetic navigation technology, a passive autonomous navigation method, is paid attention again. Geomagnetic field is a natural spatial physical field, and is a function of position and time in near earth space. The navigation technology based on geomagnetic field is researched in a wide range of commercial and military applications. This paper presents the main features and the state-of-the-art of Geomagnetic Navigation System (GMNS). Geomagnetic field models and reference maps are described. Obtaining, modeling and updating accurate Anomaly Magnetic Field information is an important step for high precision geomagnetic navigation. In addition, the errors of geomagnetic measurement using strapdown magnetometers are analyzed. The precise geomagnetic data is obtained by means of magnetometer calibration and vehicle magnetic field compensation. According to the measurement data and reference map or model of geomagnetic field, the vehicle's position and attitude can be obtained using matching algorithm or state-estimating method. The tendency of geomagnetic navigation in near future is introduced at the end of this paper.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... INTERNATIONAL TRADE COMMISSION [DN 2850] Certain Automotive GPS Navigation Systems, Components... given that the U.S. International Trade Commission has received a complaint entitled In Re Certain Automotive GPS Navigation Systems, Components Thereof, And Products Containing Same, DN 2850; the Commission...

When a Better Interface and Easy Navigation Aren't Enough: Examining the Information Architecture in a Law Enforcement Agency.

ERIC Educational Resources Information Center

Hauck, Roslin V.; Weisband, Suzanne

2002-01-01

Describes two database systems in a law enforcement agency: one is a legacy, text-based system with cumbersome navigation; the newer system is a graphical user interface with simplified navigation. Discusses results of two user studies that showed personnel preferred the older more familiar system and considers implications for system design and…

Autonomous Navigation Using Celestial Objects

NASA Technical Reports Server (NTRS)

Folta, David; Gramling, Cheryl; Leung, Dominic; Belur, Sheela; Long, Anne

1999-01-01

In the twenty-first century, National Aeronautics and Space Administration (NASA) Enterprises envision frequent low-cost missions to explore the solar system, observe the universe, and study our planet. Satellite autonomy is a key technology required to reduce satellite operating costs. The Guidance, Navigation, and Control Center (GNCC) at the Goddard Space Flight Center (GSFC) currently sponsors several initiatives associated with the development of advanced spacecraft systems to provide autonomous navigation and control. Autonomous navigation has the potential both to increase spacecraft navigation system performance and to reduce total mission cost. By eliminating the need for routine ground-based orbit determination and special tracking services, autonomous navigation can streamline spacecraft ground systems. Autonomous navigation products can be included in the science telemetry and forwarded directly to the scientific investigators. In addition, autonomous navigation products are available onboard to enable other autonomous capabilities, such as attitude control, maneuver planning and orbit control, and communications signal acquisition. Autonomous navigation is required to support advanced mission concepts such as satellite formation flying. GNCC has successfully developed high-accuracy autonomous navigation systems for near-Earth spacecraft using NASA's space and ground communications systems and the Global Positioning System (GPS). Recently, GNCC has expanded its autonomous navigation initiative to include satellite orbits that are beyond the regime in which use of GPS is possible. Currently, GNCC is assessing the feasibility of using standard spacecraft attitude sensors and communication components to provide autonomous navigation for missions including: libration point, gravity assist, high-Earth, and interplanetary orbits. The concept being evaluated uses a combination of star, Sun, and Earth sensor measurements along with forward-link Doppler measurements from the command link carrier to autonomously estimate the spacecraft's orbit and reference oscillator's frequency. To support autonomous attitude determination and control and maneuver planning and control, the orbit determination accuracy should be on the order of kilometers in position and centimeters per second in velocity. A less accurate solution (one hundred kilometers in position) could be used for acquisition purposes for command and science downloads. This paper provides performance results for both libration point orbiting and high Earth orbiting satellites as a function of sensor measurement accuracy, measurement types, measurement frequency, initial state errors, and dynamic modeling errors.

Dissociation of spatial memory systems in Williams syndrome.

PubMed

Bostelmann, Mathilde; Fragnière, Emilie; Costanzo, Floriana; Di Vara, Silvia; Menghini, Deny; Vicari, Stefano; Lavenex, Pierre; Lavenex, Pamela Banta

2017-11-01

Williams syndrome (WS), a genetic deletion syndrome, is characterized by severe visuospatial deficits affecting performance on both tabletop spatial tasks and on tasks which assess orientation and navigation. Nevertheless, previous studies of WS spatial capacities have ignored the fact that two different spatial memory systems are believed to contribute parallel spatial representations supporting navigation. The place learning system depends on the hippocampal formation and creates flexible relational representations of the environment, also known as cognitive maps. The spatial response learning system depends on the striatum and creates fixed stimulus-response representations, also known as habits. Indeed, no study assessing WS spatial competence has used tasks which selectively target these two spatial memory systems. Here, we report that individuals with WS exhibit a dissociation in their spatial abilities subserved by these two memory systems. As compared to typically developing (TD) children in the same mental age range, place learning performance was impaired in individuals with WS. In contrast, their spatial response learning performance was facilitated. Our findings in individuals with WS and TD children suggest that place learning and response learning interact competitively to control the behavioral strategies normally used to support human spatial navigation. Our findings further suggest that the neural pathways supporting place learning may be affected by the genetic deletion that characterizes WS, whereas those supporting response learning may be relatively preserved. The dissociation observed between these two spatial memory systems provides a coherent theoretical framework to characterize the spatial abilities of individuals with WS, and may lead to the development of new learning strategies based on their facilitated response learning abilities. © 2017 Wiley Periodicals, Inc.

Using neuromorphic optical sensors for spacecraft absolute and relative navigation

NASA Astrophysics Data System (ADS)

Shake, Christopher M.

We develop a novel attitude determination system (ADS) for use on nano spacecraft using neuromorphic optical sensors. The ADS intends to support nano-satellite operations by providing low-cost, low-mass, low-volume, low-power, and redundant attitude determination capabilities with quick and straightforward onboard programmability for real time spacecraft operations. The ADS is experimentally validated with commercial-off-the-shelf optical devices that perform sensing and image processing on the same circuit board and are biologically inspired by insects' vision systems, which measure optical flow while navigating in the environment. The firmware on the devices is modified to both perform the additional biologically inspired task of tracking objects and communicate with a PC/104 form-factor embedded computer running Real Time Application Interface Linux used on a spacecraft simulator. Algorithms are developed for operations using optical flow, point tracking, and hybrid modes with the sensors, and the performance of the system in all three modes is assessed using a spacecraft simulator in the Advanced Autonomous Multiple Spacecraft (ADAMUS) laboratory at Rensselaer. An existing relative state determination method is identified to be combined with the novel ADS to create a self-contained navigation system for nano spacecraft. The performance of the method is assessed in simulation and found not to match the results from its authors using only conditions and equations already published. An improved target inertia tensor method is proposed as an update to the existing relative state method, but found not to perform as expected, but is presented for others to build upon.

Intra-operative fiducial-based CT/fluoroscope image registration framework for image-guided robot-assisted joint fracture surgery.

PubMed

Dagnino, Giulio; Georgilas, Ioannis; Morad, Samir; Gibbons, Peter; Tarassoli, Payam; Atkins, Roger; Dogramadzi, Sanja

2017-08-01

Joint fractures must be accurately reduced minimising soft tissue damages to avoid negative surgical outcomes. To this regard, we have developed the RAFS surgical system, which allows the percutaneous reduction of intra-articular fractures and provides intra-operative real-time 3D image guidance to the surgeon. Earlier experiments showed the effectiveness of the RAFS system on phantoms, but also key issues which precluded its use in a clinical application. This work proposes a redesign of the RAFS's navigation system overcoming the earlier version's issues, aiming to move the RAFS system into a surgical environment. The navigation system is improved through an image registration framework allowing the intra-operative registration between pre-operative CT images and intra-operative fluoroscopic images of a fractured bone using a custom-made fiducial marker. The objective of the registration is to estimate the relative pose between a bone fragment and an orthopaedic manipulation pin inserted into it intra-operatively. The actual pose of the bone fragment can be updated in real time using an optical tracker, enabling the image guidance. Experiments on phantom and cadavers demonstrated the accuracy and reliability of the registration framework, showing a reduction accuracy (sTRE) of about [Formula: see text] (phantom) and [Formula: see text] (cadavers). Four distal femur fractures were successfully reduced in cadaveric specimens using the improved navigation system and the RAFS system following the new clinical workflow (reduction error [Formula: see text], [Formula: see text]. Experiments showed the feasibility of the image registration framework. It was successfully integrated into the navigation system, allowing the use of the RAFS system in a realistic surgical application.

Preface: BeiDou Navigation Satellite System (BDS)/GNSS+: New developments and emerging applications

NASA Astrophysics Data System (ADS)

Jin, Shuanggen

2017-12-01

The China's BeiDou Navigation Satellite System (BDS) has been developed and operated well with over 25 launched satellites in 2017, including fifteen Medium Earth orbit (MEO) satellites, five geostationary Earth orbit (GEO) satellites and five inclined geosynchronous orbit (IGSO) satellites. Together with the United States' GPS, European Union's Galileo and Russia's GLONASS as well as other regional augmentation systems, e.g., Indian Regional Navigation Satellite System (IRNSS) and Japan Quasi-Zenith Satellite System (QZSS), more emerging applications of multi-Global Navigation Satellite Systems (GNSS) will be exploited and realized in the coming years. The papers in this issue of Advances in Space Research present new advances in the system, techniques and emerging applications of BDS/GNSS+. These papers were from an open call and a special call for participants at the 8th China Satellite Navigation Conference (CSNC 2017) held on May 23-25, 2017, Shanghai, China. This conference series provides a good platform for academic and technique exchanges as well as collaboration in satellite navigation. CSNC 2017 was well attend with more than 3000 participants and over 800 papers in 12 sessions.

Space shuttle onboard navigation console expert/trainer system

NASA Technical Reports Server (NTRS)

Wang, Lui; Bochsler, Dan

1987-01-01

A software system for use in enhancing operational performance as well as training ground controllers in monitoring onboard Space Shuttle navigation sensors is described. The Onboard Navigation (ONAV) development reflects a trend toward following a structured and methodical approach to development. The ONAV system must deal with integrated conventional and expert system software, complex interfaces, and implementation limitations due to the target operational environment. An overview of the onboard navigation sensor monitoring function is presented, along with a description of guidelines driving the development effort, requirements that the system must meet, current progress, and future efforts.

An onboard navigation system which fulfills Mars aerocapture guidance requirements

NASA Technical Reports Server (NTRS)

Brand, Timothy J.; Fuhry, Douglas P.; Shepperd, Stanley W.

1989-01-01

The development of a candidate autonomous onboard Mars approach navigation scheme capable of supporting aerocapture into Mars orbit is discussed. An aerocapture guidance and navigation system which can run independently of the preaerocapture navigation was used to define a preliminary set of accuracy requirements at entry interface. These requirements are used to evaluate the proposed preaerocapture navigation scheme. This scheme uses optical sightings on Deimos with a star tracker and an inertial measurement unit for instrumentation as a source for navigation nformation. Preliminary results suggest that the approach will adequately support aerocaputre into Mars orbit.

Reliable Alignment in Total Knee Arthroplasty by the Use of an iPod-Based Navigation System

PubMed Central

Koenen, Paola; Schneider, Marco M.; Fröhlich, Matthias; Driessen, Arne; Bouillon, Bertil; Bäthis, Holger

2016-01-01

Axial alignment is one of the main objectives in total knee arthroplasty (TKA). Computer-assisted surgery (CAS) is more accurate regarding limb alignment reconstruction compared to the conventional technique. The aim of this study was to analyse the precision of the innovative navigation system DASH® by Brainlab and to evaluate the reliability of intraoperatively acquired data. A retrospective analysis of 40 patients was performed, who underwent CAS TKA using the iPod-based navigation system DASH. Pre- and postoperative axial alignment were measured on standardized radiographs by two independent observers. These data were compared with the navigation data. Furthermore, interobserver reliability was measured. The duration of surgery was monitored. The mean difference between the preoperative mechanical axis by X-ray and the first intraoperatively measured limb axis by the navigation system was 2.4°. The postoperative X-rays showed a mean difference of 1.3° compared to the final navigation measurement. According to radiographic measurements, 88% of arthroplasties had a postoperative limb axis within ±3°. The mean additional time needed for navigation was 5 minutes. We could prove very good precision for the DASH system, which is comparable to established navigation devices with only negligible expenditure of time compared to conventional TKA. PMID:27313898

The utilization of cranial models created using rapid prototyping techniques in the development of models for navigation training.

PubMed

Waran, V; Pancharatnam, Devaraj; Thambinayagam, Hari Chandran; Raman, Rajagopal; Rathinam, Alwin Kumar; Balakrishnan, Yuwaraj Kumar; Tung, Tan Su; Rahman, Z A

2014-01-01

Navigation in neurosurgery has expanded rapidly; however, suitable models to train end users to use the myriad software and hardware that come with these systems are lacking. Utilizing three-dimensional (3D) industrial rapid prototyping processes, we have been able to create models using actual computed tomography (CT) data from patients with pathology and use these models to simulate a variety of commonly performed neurosurgical procedures with navigation systems. To assess the possibility of utilizing models created from CT scan dataset obtained from patients with cranial pathology to simulate common neurosurgical procedures using navigation systems. Three patients with pathology were selected (hydrocephalus, right frontal cortical lesion, and midline clival meningioma). CT scan data following an image-guidance surgery protocol in DIACOM format and a Rapid Prototyping Machine were taken to create the necessary printed model with the corresponding pathology embedded. The ability in registration, planning, and navigation of two navigation systems using a variety of software and hardware provided by these platforms was assessed. We were able to register all models accurately using both navigation systems and perform the necessary simulations as planned. Models with pathology utilizing 3D rapid prototyping techniques accurately reflect data of actual patients and can be used in the simulation of neurosurgical operations using navigation systems. Georg Thieme Verlag KG Stuttgart · New York.

33 CFR 62.3 - Definition of terms.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Definition of terms. 62.3 Section 62.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.3 Definition of terms. Certain terms as used in this...

33 CFR 62.3 - Definition of terms.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Definition of terms. 62.3 Section 62.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.3 Definition of terms. Certain terms as used in this...

33 CFR 62.3 - Definition of terms.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Definition of terms. 62.3 Section 62.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.3 Definition of terms. Certain terms as used in this...

33 CFR 62.3 - Definition of terms.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Definition of terms. 62.3 Section 62.3 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION UNITED STATES AIDS TO NAVIGATION SYSTEM General § 62.3 Definition of terms. Certain terms as used in this...