WorldWideScience

Sample records for interplanetary navigation

  1. Dynamic Model Development for Interplanetary Navigation

    OpenAIRE

    Eun-Seo Park; Young-Joo Song; Sung-Moon Yoo; Sang-Young Park; Kyu-Hong Choi; Jae-Cheol Yoon; Jo Ryeong Yim; Joon-Min Choi; Byung-Kyo Kim

    2005-01-01

    In this paper, the dynamic model development for interplanetary navigation has been discussed. The Cowell method for special perturbation theories was employed to develop an interplanetary trajectory propagator including the perturbations due to geopotential, the Earth's dynamic polar motion, the gravity of the Sun, the Moon and the other planets in the solar system, the relativistic effect of the Sun, solar radiation pressure, and atmospheric drag. The equations of motion in dynamic model we...

  2. Dynamic Model Development for Interplanetary Navigation

    Directory of Open Access Journals (Sweden)

    Eun-Seo Park

    2005-12-01

    Full Text Available In this paper, the dynamic model development for interplanetary navigation has been discussed. The Cowell method for special perturbation theories was employed to develop an interplanetary trajectory propagator including the perturbations due to geopotential, the Earth's dynamic polar motion, the gravity of the Sun, the Moon and the other planets in the solar system, the relativistic effect of the Sun, solar radiation pressure, and atmospheric drag. The equations of motion in dynamic model were numerically integrated using Adams-Cowell 11th order predictor-corrector method. To compare the influences of each perturbation, trajectory propagation was performed using initial transfer orbit elements of the Mars Express mission launched in 2003, because it can be the criterion to choose proper perturbation models for navigation upon required accuracy. To investigate the performance of dynamic model developed, it was tested whether the spacecraft can reach the Mars. The interplanetary navigation tool developed in this study demonstrated the spacecraft entering the Mars SOI(Sphere of Influence and its velocity relative to the Mars was less than the escape velocity of the Mars, hence, the spacecraft can arrive at the target planet. The obtained results were also verified by using the AGI Satellite Tool Kit. It is concluded that the developed program is suitable for supporting interplanetary spacecraft mission for a future Korean Mars mission.

  3. Interplanetary CubeSat Navigational Challenges

    Science.gov (United States)

    Martin-Mur, Tomas J.; Gustafson, Eric D.; Young, Brian T.

    2015-01-01

    CubeSats are miniaturized spacecraft of small mass that comply with a form specification so they can be launched using standardized deployers. Since the launch of the first CubeSat into Earth orbit in June of 2003, hundreds have been placed into orbit. There are currently a number of proposals to launch and operate CubeSats in deep space, including MarCO, a technology demonstration that will launch two CubeSats towards Mars using the same launch vehicle as NASA's Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) Mars lander mission. The MarCO CubeSats are designed to relay the information transmitted by the InSight UHF radio during Entry, Descent, and Landing (EDL) in real time to the antennas of the Deep Space Network (DSN) on Earth. Other CubeSatts proposals intend to demonstrate the operation of small probes in deep space, investigate the lunar South Pole, and visit a near Earth object, among others. Placing a CubeSat into an interplanetary trajectory makes it even more challenging to pack the necessary power, communications, and navigation capabilities into such a small spacecraft. This paper presents some of the challenges and approaches for successfully navigating CubeSats and other small spacecraft in deep space.

  4. A novel interplanetary optical navigation algorithm based on Earth-Moon group photos by Chang'e-5T1 probe

    Science.gov (United States)

    Bu, Yanlong; Zhang, Qiang; Ding, Chibiao; Tang, Geshi; Wang, Hang; Qiu, Rujin; Liang, Libo; Yin, Hejun

    2017-02-01

    This paper presents an interplanetary optical navigation algorithm based on two spherical celestial bodies. The remarkable characteristic of the method is that key navigation parameters can be estimated depending entirely on known sizes and ephemerides of two celestial bodies, especially positioning is realized through a single image and does not rely on traditional terrestrial radio tracking any more. Actual Earth-Moon group photos captured by China's Chang'e-5T1 probe were used to verify the effectiveness of the algorithm. From 430,000 km away from the Earth, the camera pointing accuracy reaches 0.01° (one sigma) and the inertial positioning error is less than 200 km, respectively; meanwhile, the cost of the ground control and human resources are greatly reduced. The algorithm is flexible, easy to implement, and can provide reference to interplanetary autonomous navigation in the solar system.

  5. Interplanetary magnetohydrodynamics

    CERN Document Server

    Burlaga, Leonard F

    1995-01-01

    Spacecraft such as the Pioneer, Vela, and Voyager have explored the interplanetary medium between the orbits of Mercury and Pluto. The insights derived from these missions have been successfully applied to magnetospheric, astro-solar, and cosmic ray physics. This book is an overview of these insights, using magnetohydrodynamic (MHD) flows as the framework for interpreting objects and processes observed in the interplanetary medium. Topics include various types of MHD shocks and interactions among them, tangential and rotational discontinuities, force-free field configurations, the formation of merged interaction regions associated with various types of flows, the destruction of flows, the growth of the Kelvin-Helmholtz instability and formation of a heliospheric vortex street, the development of multifractal fluctuations on various scales, and the evolution of multifractal intermittent turbulence. Students and researchers in astrophysics will value the data from these missions, which provide confirmation of m...

  6. Multifrequency techniques for studying interplanetary scintillations

    International Nuclear Information System (INIS)

    Woo, R.

    1975-01-01

    Rytov's approximation or the method of smooth perturbations is utilized to derive the temporal frequency spectra of the amplitude and phase fluctuations of multifrequency plane and spherical waves propagating in the interplanetary medium and solar corona. It is shown that multifrequency observations of interplanetary scintillations using either compact radio stars or spacecraft radio signals are desirable because the correlation of the multifrequency waves yields additional independent measurements of the solar wind and turbulence. Measurements of phase fluctuations are also desirable because, unlike amplitude fluctuations, they provide information on the full range of scale sizes for the electron density fluctuations. It is shown that a coherent dual-frequency radio system is particularly useful in making such measurements. In addition to providing a means for interpreting observations of multifrequency interplanetary scintillations, the analysis is also essential for estimating the effects of solar corona turbulence on the communications and navigation of a spacecraft whose line-of-sight path passes close to the Sun

  7. Solar and interplanetary disturbances

    CERN Document Server

    Alurkar, S K

    1997-01-01

    Over the last three decades, a spate of solar wind observations have been made with sophisticated ground-based and space-borne instruments. Two highly successful space missions of the Skylab and the twin spacecraft Helios 1 and 2 have amassed an invaluable wealth of information on the large scale structure of the inner heliosphere, the solar and interplanetary magnetic field, coronal holes, interplanetary dust, solar windflows, etc.Solar and interplanetary propagating phenomena have been extensively studied during the last two decades. Very recently, a new simple model based on results from a

  8. Lunar and interplanetary trajectories

    CERN Document Server

    Biesbroek, Robin

    2016-01-01

    This book provides readers with a clear description of the types of lunar and interplanetary trajectories, and how they influence satellite-system design. The description follows an engineering rather than a mathematical approach and includes many examples of lunar trajectories, based on real missions. It helps readers gain an understanding of the driving subsystems of interplanetary and lunar satellites. The tables and graphs showing features of trajectories make the book easy to understand. .

  9. Multifrequency techniques for studying interplanetary scintillations

    Science.gov (United States)

    Woo, R.

    1975-01-01

    Rytov's approximation, or the method of smooth perturbations, is utilized to derive the temporal frequency spectra of the amplitude and phase fluctuations of multifrequency plane and spherical waves propagating in the interplanetary medium and solar corona. It is shown that multifrequency observations of interplanetary scintillations using either compact radio stars of spacecraft radio signals are desirable because the correlation of the multifrequency waves yields additional independent measurements of the solar wind and turbulence. Measurements of phase fluctuations are also desirable because, unlike amplitude fluctuations, they provide information on the full range of scale sizes for the electron-density fluctuations. It is also shown that a coherent dual-frequency radio system is particularly useful in making such measurements. In addition to providing a means for interpreting observations of multifrequency interplanetary scintillations, the present analysis is essential for estimating the effects of solar corona turbulence on the communications and navigation of a spacecraft whose line-of-sight path passes close to the sun.

  10. Interplanetary Dust Particles

    Science.gov (United States)

    Bradley, J. P.

    2003-12-01

    micrometeorites) containing layer silicates indicative of parent-body aqueous alteration and the more distant anhydrous P and D asteroids exhibiting no evidence of (aqueous) alteration (Gradie and Tedesco, 1982). This gradation in spectral properties presumably extends several hundred AU out to the Kuiper belt, the source region of most short-period comets, where the distinction between comets and outer asteroids may simply be one of the orbital parameters ( Luu, 1993; Brownlee, 1994; Jessberger et al., 2001). The mineralogy and petrography of meteorites provides direct confirmation of aqueous alteration, melting, fractionation, and thermal metamorphism among the inner asteroids ( Zolensky and McSween, 1988; Farinella et al., 1993; Brearley and Jones, 1998). Because the most common grains in the ISM (silicates and carbonaceous matter) are not as refractory as those found in meteorites, it is unlikely that they have survived in significant quantities in meteorites. Despite a prolonged search, not a single presolar silicate grain has yet been identified in any meteorite.Interplanetary dust particles (IDPs) are the smallest and most fine-grained meteoritic objects available for laboratory investigation (Figure 1). In contrast to meteorites, IDPs are derived from a broad range of dust-producing bodies extending from the inner main belt of the asteroids to the Kuiper belt (Flynn, 1996, 1990; Dermott et al., 1994; Liou et al., 1996). After release from their asteroidal or cometary parent bodies the orbits of IDPs evolve by Poynting-Robertson (PR) drag (the combined influence of light pressure and radiation drag) ( Dermott et al., 2001). Irrespective of the location of their parent bodies nearly all IDPs under the influence of PR drag can eventually reach Earth-crossing orbits. IDPs are collected in the stratosphere at 20-25 km altitude using NASA ER2 aircraft ( Sandford, 1987; Warren and Zolensky, 1994). Laboratory measurements of implanted rare gases, solar flare tracks ( Figure 2

  11. Evolving Coronal Holes and Interplanetary Erupting Stream ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Coronal holes and interplanetary disturbances are important aspects of the physics of the Sun and heliosphere. Interplanetary disturbances are identified as an increase in the density turbulence compared with the ambient solar wind. Erupting stream disturbances are transient large-scale structures of ...

  12. Evolving Coronal Holes and Interplanetary Erupting Stream ...

    Indian Academy of Sciences (India)

    Abstract. Coronal holes and interplanetary disturbances are important aspects of the physics of the Sun and heliosphere. Interplanetary distur- bances are identified as an increase in the density turbulence compared with the ambient solar wind. Erupting stream disturbances are transient large-scale structures of enhanced ...

  13. Solar and Interplanetary Disturbances causing Moderate ...

    Indian Academy of Sciences (India)

    Abstract. The effect of solar and interplanetary disturbances on geo- magnetospheric conditions leading to 121 moderate geomagnetic storms. (MGS) have been investigated using the neutron monitor, solar geophysical and interplanetary data during the period 1978–99. Further, the duration of recovery phase has been ...

  14. Transceiver optics for interplanetary communications

    Science.gov (United States)

    Roberts, W. T.; Farr, W. H.; Rider, B.; Sampath, D.

    2017-11-01

    In-situ interplanetary science missions constantly push the spacecraft communications systems to support successively higher downlink rates. However, the highly restrictive mass and power constraints placed on interplanetary spacecraft significantly limit the desired bandwidth increases in going forward with current radio frequency (RF) technology. To overcome these limitations, we have evaluated the ability of free-space optical communications systems to make substantial gains in downlink bandwidth, while holding to the mass and power limits allocated to current state-of-the-art Ka-band communications systems. A primary component of such an optical communications system is the optical assembly, comprised of the optical support structure, optical elements, baffles and outer enclosure. We wish to estimate the total mass that such an optical assembly might require, and assess what form it might take. Finally, to ground this generalized study, we should produce a conceptual design, and use that to verify its ability to achieve the required downlink gain, estimate it's specific optical and opto-mechanical requirements, and evaluate the feasibility of producing the assembly.

  15. CLIpSAT for Interplanetary Missions: Common Low-cost Interplanetary Spacecraft with Autonomy Technologies

    Science.gov (United States)

    Grasso, C.

    2015-10-01

    Blue Sun Enterprises, Inc. is creating a common deep space bus capable of a wide variety of Mars, asteroid, and comet science missions, observational missions in and near GEO, and interplanetary delivery missions. The spacecraft are modular and highly autonomous, featuring a common core and optional expansion for variable-sized science or commercial payloads. Initial spacecraft designs are targeted for Mars atmospheric science, a Phobos sample return mission, geosynchronous reconnaissance, and en-masse delivery of payloads using packetized propulsion modules. By combining design, build, and operations processes for these missions, the cost and effort for creating the bus is shared across a variety of initial missions, reducing overall costs. A CLIpSAT can be delivered to different orbits and still be able to reach interplanetary targets like Mars due to up to 14.5 km/sec of delta-V provided by its high-ISP Xenon ion thruster(s). A 6U version of the spacecraft form fits PPOD-standard deployment systems, with up to 9 km/s of delta-V. A larger 12-U (with the addition of an expansion module) enables higher overall delta-V, and has the ability to jettison the expansion module and return to the Earth-Moon system from Mars orbit with the main spacecraft. CLIpSAT utilizes radiation-hardened electronics and RF equipment, 140+ We of power at earth (60 We at Mars), a compact navigation camera that doubles as a science imager, and communications of 2000 bps from Mars to the DSN via X-band. This bus could form the cornerstone of a large number asteroid survey projects, comet intercept missions, and planetary observation missions. The TugBot architecture uses groups of CLIpSATs attached to payloads lacking innate high-delta-V propulsion. The TugBots use coordinated trajectory following by each individual spacecraft to move the payload to the desired orbit - for example, a defense asset might be moved from GEO to lunar transfer orbit in order to protect and hide it, then returned

  16. CFDP for Interplanetary Overlay Network

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for Interplanetary Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.

  17. Interplanetary magnetic field and geomagnetic Dst variations.

    Science.gov (United States)

    Patel, V. L.; Desai, U. D.

    1973-01-01

    The interplanetary magnetic field has been shown to influence the ring current field represented by Dst. Explorer 28 hourly magnetic field observations have been used with the hourly Dst values. The moderate geomagnetic storms of 60 gammas and quiet-time fluctuations of 10 to 30 gammas are correlated with the north to south change of the interplanetary field component perpendicular to the ecliptic. This change in the interplanetary field occurs one to three hours earlier than the corresponding change in the Dst field.

  18. Deep Space Network Measurement Model Development for Interplanetary Mission

    Directory of Open Access Journals (Sweden)

    Hae-Yeon Kim

    2004-12-01

    Full Text Available The DSN(Deep Space Network measurement model for interplanetary navigations which is essential for precise orbit determination has been developed. The DSN measurement model produces fictitious DSN observables such as range, doppler and angular data, containing the potential observational errors in geometric data obtained from orbit propagator. So the important part of this research is to model observational errors in DSN observation and to characterize the errors. The modeled observational errors include the range delay effect caused by troposphere, ionosphere, antenna offset, and angular refraction effect caused by troposphere. Non-modeled errors are justified %%as the solved-for parameters. as the parameters. All of these results from developed models show about 10% errors compared to the JPL's reference results, that are within acceptable error range.

  19. Interplanetary Small Satellite Conference 2017 Program

    Science.gov (United States)

    Dalle, Derek Jordan

    2017-01-01

    The Interplanetary Small Satellite Conference will be held at San Jose State University on May 1 and 2, 2017. The program attached here contains logistical information for attendees, the agenda, and abstracts of the conference presentations. All abstracts were reviewed by their authors' home institute and approved for public release prior to inclusion in the program booklet. The ISSC explores mission concepts, emerging technologies, and fosters outside the box thinking critical to future interplanetary small satellite missions.

  20. Dust in the interplanetary medium

    Energy Technology Data Exchange (ETDEWEB)

    Mann, Ingrid; Lamy, Herve [Belgian Institute for Space Aeronomy, Brussels (Belgium); Czechowski, Andrzej [Space Research Center, Polish Academy of Sciences, Warsaw (Poland); Meyer-Vernet, Nicole; Zaslavsky, Arnaud, E-mail: ingrid.mann@aeronomie.b [LESIA, Observatoire de Paris, Meudon (France)

    2010-12-15

    The mass density of dust particles that form from asteroids and comets in the interplanetary medium of the solar system is, near 1 AU, comparable to the mass density of the solar wind. It is mainly contained in particles of micrometer size and larger. Dust and larger objects are destroyed by collisions and sublimation and hence feed heavy ions into the solar wind and the solar corona. Small dust particles are present in large number and as a result of their large charge to mass ratio deflected by electromagnetic forces in the solar wind. For nanodust particles of sizes {approx_equal}1-10 nm, recent calculations show trapping near the Sun and outside from about 0.15 AU ejection with velocities close to solar wind velocity. The fluxes of ejected nanodust are detected near 1 AU with the plasma wave instrument onboard the STEREO spacecraft. Although such electric signals have been observed during dust impacts before, the interpretation depends on several different parameters and data analysis is still in progress.

  1. Electron heating at interplanetary shocks

    International Nuclear Information System (INIS)

    Feldman, W.C.; Asbridge, J.R.; Bame, S.J.; Gosling, J.T.; Zwickl, R.D.

    1982-01-01

    Data for 41 forward interplanetary shocks measured between August 1978 and December 1979 show that the ratio of downstream to upstream electron temperatures, T/sub e/(d/u) is variable in the range between 1.0 (isothermal) and 3.0. On average, (T/sub e/(d/u) = 1.5 with a standard deviation, sigma e = 0.5. This ratio is less than the average ratio of proton temperatures across the same shocks, (T/sub p/(d/u)) = 3.3 with sigma p = 2.5 as well as the average ratio of electron temperatures across the earth's bow shock. Individual samples of T/sub e/(d/u) and T/sub p/(d/u) appear to be weakly correlated with the number density ratio. However the amounts of electron and proton heating are well correlated with each other as well as with the bulk velocity difference across each shock. The stronger shocks appear to heat the protons relatively more efficiently than they heat the electrons

  2. Analysing Interplanetary Probe Guidance Accuracy

    Directory of Open Access Journals (Sweden)

    S. V. Sukhova

    2016-01-01

    Full Text Available The paper presents a guidance accuracy analysis and estimates delta-v budget required to provide the trajectory correction maneuvers for direct interplanetary flights (without midcourse gravity assists. The analysis takes into consideration the orbital hyperbolic injection errors (depend on a selected launch vehicle and ascent trajectory and the uncertainties of midcourse correction maneuvers.The calculation algorithm is based on Monte Carlo simulation and Danby’s matrix methods (the matrizant of keplerian motion. Danby’s method establishes a link between the errors of the spacecraft state vectors at different flight times using the reference keplerian orbit matrizant. Utilizing the nominal trajectory parameters and the covariance matrix of launch vehicle injection errors the random perturbed orbits are generated and required velocity corrections are calculated. The next step is to simulate midcourse maneuver performance uncertainty using the midcourse maneuver covariance matrix. The obtained trajectory correction impulses and spacecraft position errors are statistically processed to compute required delta-v budget and dispersions ellipse parameters for different prediction intervals.As an example, a guidance accuracy analysis has been conducted for a 2022 mission to Mars and a Venus mission in 2026. The paper considers one and two midcourse correction options, as well as utilization of two different launch vehicles.The presented algorithm based on Monte Carlo simulation and Danby’s methods provides preliminary evaluation for midcourse corrections delta-v budget and spacecraft position error. The only data required for this guidance accuracy analysis are a reference keplerian trajectory and a covariance matrix of the injection errors. Danby’s matrix method allows us to take into account also the other factors affecting the trajectory thereby increasing the accuracy of analysis.

  3. Intermittent character of interplanetary magnetic field fluctuations

    International Nuclear Information System (INIS)

    Bruno, Roberto; Carbone, Vincenzo; Chapman, Sandra; Hnat, Bogdan; Noullez, Alain; Sorriso-Valvo, Luca

    2007-01-01

    Interplanetary magnetic field magnitude fluctuations are notoriously more intermittent than velocity fluctuations in both fast and slow wind. This behavior has been interpreted in terms of the anomalous scaling observed in passive scalars in fully developed hydrodynamic turbulence. In this paper, the strong intermittent nature of the interplanetary magnetic field is briefly discussed comparing results performed during different phases of the solar cycle. The scaling properties of the interplanetary magnetic field magnitude show solar cycle variation that can be distinguished in the scaling exponents revealed by structure functions. The scaling exponents observed around the solar maximum coincide, within the errors, to those measured for passive scalars in hydrodynamic turbulence. However, it is also found that the values are not universal in the sense that the solar cycle variation may be reflected in dependence on the structure of the velocity field

  4. International Launch Vehicle Selection for Interplanetary Travel

    Science.gov (United States)

    Ferrone, Kristine; Nguyen, Lori T.

    2010-01-01

    In developing a mission strategy for interplanetary travel, the first step is to consider launch capabilities which provide the basis for fundamental parameters of the mission. This investigation focuses on the numerous launch vehicles of various characteristics available and in development internationally with respect to upmass, launch site, payload shroud size, fuel type, cost, and launch frequency. This presentation will describe launch vehicles available and in development worldwide, then carefully detail a selection process for choosing appropriate vehicles for interplanetary missions focusing on international collaboration, risk management, and minimization of cost. The vehicles that fit the established criteria will be discussed in detail with emphasis on the specifications and limitations related to interplanetary travel. The final menu of options will include recommendations for overall mission design and strategy.

  5. Interplanetary Magnetic Field Guiding Relativistic Particles

    Science.gov (United States)

    Masson, S.; Demoulin, P.; Dasso, S.; Klein, K. L.

    2011-01-01

    The origin and the propagation of relativistic solar particles (0.5 to few Ge V) in the interplanetary medium remains a debated topic. These relativistic particles, detected at the Earth by neutron monitors have been previously accelerated close to the Sun and are guided by the interplanetary magnetic field (IMF) lines, connecting the acceleration site and the Earth. Usually, the nominal Parker spiral is considered for ensuring the magnetic connection to the Earth. However, in most GLEs the IMF is highly disturbed, and the active regions associated to the GLEs are not always located close to the solar footprint of the nominal Parker spiral. A possible explanation is that relativistic particles are propagating in transient magnetic structures, such as Interplanetary Coronal Mass Ejections (ICMEs). In order to check this interpretation, we studied in detail the interplanetary medium where the particles propagate for 10 GLEs of the last solar cycle. Using the magnetic field and the plasma parameter measurements (ACE/MAG and ACE/SWEPAM), we found widely different IMF configurations. In an independent approach we develop and apply an improved method of the velocity dispersion analysis to energetic protons measured by SoHO/ERNE. We determined the effective path length and the solar release time of protons from these data and also combined them with the neutron monitor data. We found that in most of the GLEs, protons propagate in transient magnetic structures. Moreover, the comparison between the interplanetary magnetic structure and the interplanetary length suggest that the timing of particle arrival at Earth is dominantly determined by the type of IMF in which high energetic particles are propagating. Finally we find that these energetic protons are not significantly scattered during their transport to Earth.

  6. Interplanetary Space Weather and Its Planetary Connection

    Science.gov (United States)

    Crosby, Norma; Bothmer, Volker; Facius, Rainer; Grießmeier, Jean-Mathias; Moussas, Xenophon; Panasyuk, Mikhail; Romanova, Natalia; Withers, Paul

    2008-01-01

    Interplanetary travel is not just a science fiction scenario anymore, but a goal as realistic as when our ancestors started to cross the oceans. With curiosity driving humans to visit other planets in our solar system, the understanding of interplanetary space weather is a vital subject today, particularly because the physical conditions faced during a space vehicle's transit to its targeted solar system object are crucial to a mission's success and vital to the health and safety of spacecraft crew, especially when scheduling planned extravehicular activities.

  7. Evolution of coronal and interplanetary magnetic fields

    International Nuclear Information System (INIS)

    Levine, R.H.

    1980-01-01

    Numerous studies have provided the detailed information necessary for a substantive synthesis of the empirical relation between the magnetic field of the sun and the structure of the interplanetary field. The author points out the latest techniques and studies of the global solar magnetic field and its relation to the interplanetary field. The potential to overcome most of the limitations of present methods of analysis exists in techniques of modelling the coronal magnetic field using observed solar data. Such empirical models are, in principle, capable of establishing the connection between a given heliospheric point and its magnetically-connected photospheric point, as well as the physical basis for the connection. (Auth.)

  8. Relationship between Interplanetary (IP) Parameters and ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... In the present study, we investigate the possible relationship of IP parameters of solar wind and interplanetary magnetic field with ground-based geomagnetic indices. To carry out the study, we take all the IP shock events listed by Proton Monitor onboard Solar and Heliospheric Observatory (SOHO) during ...

  9. Relationship between Interplanetary (IP) Parameters and ...

    Indian Academy of Sciences (India)

    3SITAA-SAC, Indian Space Research Organisation, Ahmedabad, Gujarat 380 015, India. 4Indian Space Research Organisation-Head Quarters, Bangalore, Karnataka, India. Abstract. In the present study, .... Lepping, R. P., Jones, J. A., Burlaga, L. F. 1990, Magnetic field structure of Interplanetary. Magnetic Clouds at 1 A.U; ...

  10. Geomagnetic response to solar and interplanetary disturbances

    Czech Academy of Sciences Publication Activity Database

    Saiz, E.; Cerrato, Y.; Cid, C.; Dobrica, V.; Hejda, Pavel; Nenovski, P.; Stauning, P.; Bochníček, Josef; Danov, D.; Demetrescu, C.; Gonzalez, W. D.; Maris, G.; Teodosiev, D.; Valach, F.

    2013-01-01

    Roč. 3, July (2013), A26/1-A26/20 ISSN 2115-7251 R&D Projects: GA MŠk OC09070 Institutional support: RVO:67985530 Keywords : solar activity * interplanetary medium * indices * ionosphere (general) * ring current Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 2.519, year: 2013

  11. Relationship between Interplanetary (IP) Parameters and ...

    Indian Academy of Sciences (India)

    An active Sun spews out concentrated particle and field energy into interplanetary space (IP), and manifestations of these have been studied by many researchers (to mention a few,. Cargill 2000; Lepping et al. 1990; Gopalswamy et al. 2004; Bothmer & Schwenn. 1998). Propagation of these emissions through IP space and ...

  12. Solar and Interplanetary Disturbances causing Moderate ...

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Keywords. Solar flares; active prominences and disappearing filaments; sunspot numbers; geomagnetic storms. Abstract. The effect of solar and interplanetary disturbances on geomagnetospheric conditions leading to 121 moderate geomagnetic storms (MGS) have been investigated using the neutron ...

  13. Ecodesign Navigator

    DEFF Research Database (Denmark)

    Simon, M; Evans, S.; McAloone, Timothy Charles

    The Ecodesign Navigator is the product of a three-year research project called DEEDS - DEsign for Environment Decision Support. The initial partners were Manchester Metropolitan University, Cranfield University, Engineering 6 Physical Sciences Resaech Council, Electrolux, ICL, and the Industry Co...... Council For Electronic Equipment Recycling....

  14. Software Risk Identification for Interplanetary Probes

    Science.gov (United States)

    Dougherty, Robert J.; Papadopoulos, Periklis E.

    2005-01-01

    The need for a systematic and effective software risk identification methodology is critical for interplanetary probes that are using increasingly complex and critical software. Several probe failures are examined that suggest more attention and resources need to be dedicated to identifying software risks. The direct causes of these failures can often be traced to systemic problems in all phases of the software engineering process. These failures have lead to the development of a practical methodology to identify risks for interplanetary probes. The proposed methodology is based upon the tailoring of the Software Engineering Institute's (SEI) method of taxonomy-based risk identification. The use of this methodology will ensure a more consistent and complete identification of software risks in these probes.

  15. Interplanetary Alfvenic fluctuations: A stochastic model

    International Nuclear Information System (INIS)

    Barnes, A.

    1981-01-01

    The strong alignment of the average directions of minimum magnetic variance and mean magnetic field in interplanetary Alfvenic fluctuations is inconsistent with the usual wave-propagation models. We investigate the concept of minimum variance for nonplanar Alfvenic fluctuations in which the field direction varies stochastically. It is found that the tendency of the minimum variance and mean field directions to be aligned may be purely a consequence of the randomness of the field direction. In particular, a well-defined direction of minimum variance does not imply that the fluctuations are necessarily planar. The fluctuation power spectrum is a power law for frequencies much higher than the inverse of the correlation time. The probability distribution of directions a randomly fluctuating field of constant magnitude is calculated. A new approach for observational studies of interplanetary fluctuations is suggested

  16. Modelling interplanetary CMEs using magnetohydrodynamic simulations

    Directory of Open Access Journals (Sweden)

    P. J. Cargill

    Full Text Available The dynamics of Interplanetary Coronal Mass Ejections (ICMEs are discussed from the viewpoint of numerical modelling. Hydrodynamic models are shown to give a good zero-order picture of the plasma properties of ICMEs, but they cannot model the important magnetic field effects. Results from MHD simulations are shown for a number of cases of interest. It is demonstrated that the strong interaction of the ICME with the solar wind leads to the ICME and solar wind velocities being close to each other at 1 AU, despite their having very different speeds near the Sun. It is also pointed out that this interaction leads to a distortion of the ICME geometry, making cylindrical symmetry a dubious assumption for the CME field at 1 AU. In the presence of a significant solar wind magnetic field, the magnetic fields of the ICME and solar wind can reconnect with each other, leading to an ICME that has solar wind-like field lines. This effect is especially important when an ICME with the right sense of rotation propagates down the heliospheric current sheet. It is also noted that a lack of knowledge of the coronal magnetic field makes such simulations of little use in space weather forecasts that require knowledge of the ICME magnetic field strength.

    Key words. Interplanetary physics (interplanetary magnetic fields Solar physics, astrophysics, and astronomy (flares and mass ejections Space plasma physics (numerical simulation studies

  17. The near-Earth and interplanetary plasma

    International Nuclear Information System (INIS)

    Al'pert, Y.L.

    1983-01-01

    This monograph is an extensive revision and expansion of the original paper which first appeared in 1976 in the encyclopedia, Handbuch der Physik. It presents a detailed and comprehensive treatment of wave processes and of the motion of bodies through plasma around moving bodies such as artificial satellites, and with natural plasma waves and oscillations. Contents, abridged: General properties of the near-Earth and interplanetary plasma. Refractive indexes of cold magnetoplasma. Growth rates for the different oscillation branches. Nonlinear effects in a plasma. Group velocity, trajectories, and trapping of electromagnetic waves in a magnetoplasma. Indexes

  18. Radio emission from coronal and interplanetary shocks

    International Nuclear Information System (INIS)

    Cane, H.V.

    1987-01-01

    Observational data on coronal and interplanetary (IP) type II burst events associated with shock-wave propagation are reviewed, with a focus on the past and potential future contributions of space-based observatories. The evidence presented by Cane (1983 and 1984) in support of the hypothesis that the coronal (metric) and IP (kilometric) bursts are due to different shocks is summarized, and the fast-drift kilometric events seen at the same time as metric type II bursts (and designated shock-accelerated or shock-associated events) are characterized. The need for further observations at 0.5-20 MHz is indicated. 20 references

  19. Nonthermal Radiation Processes in Interplanetary Plasmas

    Science.gov (United States)

    Chian, A. C. L.

    1990-11-01

    RESUMEN. En la interacci6n de haces de electrones energeticos con plasmas interplanetarios, se excitan ondas intensas de Langmuir debido a inestabilidad del haz de plasma. Las ondas Langmuir a su vez interaccio nan con fluctuaciones de densidad de baja frecuencia para producir radiaciones. Si la longitud de las ondas de Langmujr exceden las condicio nes del umbral, se puede efectuar la conversi5n de modo no lineal a on- das electromagneticas a traves de inestabilidades parametricas. As se puede excitar en un plasma inestabilidades parametricas electromagneticas impulsadas por ondas intensas de Langmuir: (1) inestabilidades de decaimiento/fusi5n electromagnetica impulsadas por una bomba de Lang- muir que viaja; (2) inestabilidades dobles electromagneticas de decai- miento/fusi5n impulsadas por dos bombas de Langrnuir directamente opues- tas; y (3) inestabilidades de dos corrientes oscilatorias electromagne- ticas impulsadas por dos bombas de Langmuir de corrientes contrarias. Se concluye que las inestabilidades parametricas electromagneticas in- ducidas por las ondas de Langmuir son las fuentes posibles de radiacio- nes no termicas en plasmas interplanetarios. ABSTRACT: Nonthermal radio emissions near the local electron plasma frequency have been detected in various regions of interplanetary plasmas: solar wind, upstream of planetary bow shock, and heliopause. Energetic electron beams accelerated by solar flares, planetary bow shocks, and the terminal shock of heliosphere provide the energy source for these radio emissions. Thus, it is expected that similar nonthermal radiation processes may be responsible for the generation of these radio emissions. As energetic electron beams interact with interplanetary plasmas, intense Langmuir waves are excited due to a beam-plasma instability. The Langmuir waves then interact with low-frequency density fluctuations to produce radiations near the local electron plasma frequency. If Langmuir waves are of sufficiently large

  20. Tomography of the Solar Wind using Interplanetary Scintillation ...

    Indian Academy of Sciences (India)

    tribpo

    Tomography—solar wind—interplanetary scintillation. Extended abstract. Interplanetary ... properties of solar wind (SW) along the line of sight (los) to a distant compact radio source. Mapping a los back to ... power spectra of intensity fluctuations, the primary IPS observable, constructed using the distribution of properties of ...

  1. Evolution and interaction of large interplanetary streams

    International Nuclear Information System (INIS)

    Whang, Y.C.; Burlaga, L.F.

    1985-02-01

    A computer simulation for the evolution and interaction of large interplanetary streams based on multi-spacecraft observations and an unsteady, one-dimensional MHD model is presented. Two events, each observed by two or more spacecraft separated by a distance of the order of 10 AU, were studied. The first simulation is based on the plasma and magnetic field observations made by two radially-aligned spacecraft. The second simulation is based on an event observed first by Helios-1 in May 1980 near 0.6 AU and later by Voyager-1 in June 1980 at 8.1 AU. These examples show that the dynamical evolution of large-scale solar wind structures is dominated by the shock process, including the formation, collision, and merging of shocks. The interaction of shocks with stream structures also causes a drastic decrease in the amplitude of the solar wind speed variation with increasing heliocentric distance, and as a result of interactions there is a large variation of shock-strengths and shock-speeds. The simulation results shed light on the interpretation for the interaction and evolution of large interplanetary streams. Observations were made along a few limited trajectories, but simulation results can supplement these by providing the detailed evolution process for large-scale solar wind structures in the vast region not directly observed. The use of a quantitative nonlinear simulation model including shock merging process is crucial in the interpretation of data obtained in the outer heliosphere

  2. Surgical Navigation

    DEFF Research Database (Denmark)

    Azarmehr, Iman; Stokbro, Kasper; Bell, R. Bryan

    2017-01-01

    body removal, respectively. The average technical system accuracy and intraoperative precision reported were less than 1 mm and 1 to 2 mm, respectively. In general, SN is reported to be a useful tool for surgical planning, execution, evaluation, and research. The largest numbers of studies and patients......Purpose: This systematic review investigates the most common indications, treatments, and outcomes of surgical navigation (SN) published from 2010 to 2015. The evolution of SN and its application in oral and maxillofacial surgery have rapidly developed over recent years, and therapeutic indications...... surgery, skull-base surgery, and foreign body removal were the areas of interests. Results: The search generated 13 articles dealing with traumatology; 5, 6, 2, and 0 studies were found that dealt with the topics of orthognathic surgery, cancer and reconstruction surgery, skull-base surgery, and foreign...

  3. Navigation Lights - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  4. Trailblazing Medicine Sustaining Explorers During Interplanetary Missions

    CERN Document Server

    Seedhouse, Erik

    2011-01-01

    To prepare for the day when astronauts leave low-Earth orbit for long-duration exploration missions, space medicine experts must develop a thorough understanding of the effects of microgravity on the human body, as well as ways of mitigating them. To gain a complete understanding of the effects of space on the human body and to create tools and technologies required for successful exploration, space medicince will become an increasingly collaborative discipline incorporating the skills of physicians, biomedical scientists, engineers, and mission planners. Trailblazing Medicine examines the future of space medicine in relation to human space exploration; describes what is necessary to keep a crew alive in space, including the use of surgical robots, surface-based telemedicine, and remote emergency care; discusses bioethical problems such as euthanasia, sex, and precautionary surgery; investigates the medical challenges faced by interplanetary astronauts; details the process of human hibernation.

  5. Magnetospheric and interplanetary physics 1979-1982

    Science.gov (United States)

    Stern, D. P.

    1983-01-01

    Major trends in the study of magnetospheric and interplanetary physics during the 1979-1982 period are surveyed. Topics discussed include the exploration of the Saturnian and Jovian magnetospheres by Voyagers 1 and 2, the behavior of different ions in the earth magnetosphere, auroral kilometric radiation, computer modeling of global magnetospheric MHD flow, the magnetic substorm, the quiet state, the earth's bow shock, the heliospheric current sheet, and new techniques such as electron beam experiments, 'active' injection experiments, auroral radars, and observations of the earth's distant magnetic tail. The future of this area of research is seen in the combination of data from different spacecraft and ground observations in a single correlated data set, and in the consolidation of past gains by analysis of the large data backlog, while a small number of new missions goes forward.

  6. Laser-fusion rocket for interplanetary propulsion

    International Nuclear Information System (INIS)

    Hyde, R.A.

    1983-01-01

    A rocket powered by fusion microexplosions is well suited for quick interplanetary travel. Fusion pellets are sequentially injected into a magnetic thrust chamber. There, focused energy from a fusion Driver is used to implode and ignite them. Upon exploding, the plasma debris expands into the surrounding magnetic field and is redirected by it, producing thrust. This paper discusses the desired features and operation of the fusion pellet, its Driver, and magnetic thrust chamber. A rocket design is presented which uses slightly tritium-enriched deuterium as the fusion fuel, a high temperature KrF laser as the Driver, and a thrust chamber consisting of a single superconducting current loop protected from the pellet by a radiation shield. This rocket can be operated with a power-to-mass ratio of 110 W gm -1 , which permits missions ranging from occasional 9 day VIP service to Mars, to routine 1 year, 1500 ton, Plutonian cargo runs

  7. Simulating the Liaison Navigation Concept in a Geo + Earth-Moon Halo Constellation

    Science.gov (United States)

    Fujimoto, K.; Leonard, J. M.; McGranaghan, R. M.; Parker, J. S.; Anderson, R. L.; Born, G. H.

    2012-01-01

    Linked Autonomous Interplanetary Satellite Orbit Navigation, or LiAISON, is a novel satellite navigation technique where relative radiometric measurements between two or more spacecraft in a constellation are processed to obtain the absolute state of all spacecraft. The method leverages the asymmetry of the gravity field that the constellation exists in. This paper takes a step forward in developing a high fidelity navigation simulation for the LiAISON concept in an Earth-Moon constellation. In particular, we aim to process two-way Doppler measurements between a satellite in GEO orbit and another in a halo orbit about the Earth-Moon L1 point.

  8. Physical Characteristics of Coronal Region Driving Out the Interplanetary Shock

    Directory of Open Access Journals (Sweden)

    Su Yeon Oh

    2008-03-01

    Full Text Available Using the solar wind data of 2000 observed by ACE, We classified the interplanetary shock on basis of shock driver. We examined the physical properties of shock drivers such as the ratio of charge states(O7/O6 and thermal index(I_{th}. Most of 51 interplanetary shocks are driven by interplanetary coronal mass ejections(ICME; magnetic cloud and ejecta and high speed streams. According to the test of temperature(O7/O6 and I_{th}, we found that ICMEs originated from region with hot source in corona.

  9. Multi-Purpose Interplanetary Deployable Aerocapture System (MIDAS) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Altius Space Machines and MSNW LLC propose the development of a cubesat-scale Multipurpose Interplanetary Deployable Aerocapture System (MIDAS), to provide cubesats...

  10. Fast, Autonomous Chemical Interplanetary Mission Design via Hybrid Optimal Control

    Data.gov (United States)

    National Aeronautics and Space Administration — Interplanetary mission design is historically a complex and expensive process requiring many human-hours of work. This proposal outlines a novel technique for...

  11. Radar Characterization of the Interplanetary Meteoroid Environment, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a new modeling effort that will make substantial refinements and improvements to our existing models of the interplanetary meteoroid environment near...

  12. Optimizing Materials for Energy Harvesting on Interplanetary Return Missions

    Data.gov (United States)

    National Aeronautics and Space Administration — Manned interplanetary missions will only be desirable once the ability to return is established. Even using improved fuel technologies we have not resourced the fuel...

  13. Machine learning and evolutionary techniques in interplanetary trajectory design

    OpenAIRE

    Izzo, Dario; Sprague, Christopher; Tailor, Dharmesh

    2018-01-01

    After providing a brief historical overview on the synergies between artificial intelligence research, in the areas of evolutionary computations and machine learning, and the optimal design of interplanetary trajectories, we propose and study the use of deep artificial neural networks to represent, on-board, the optimal guidance profile of an interplanetary mission. The results, limited to the chosen test case of an Earth-Mars orbital transfer, extend the findings made previously for landing ...

  14. Water and organics in interplanetary dust particles

    Science.gov (United States)

    Bradley, John

    Interplanetary dust particles (IDPs) and larger micrometeorites (MMs) impinge on the upper atmosphere where they decelerate at 90 km altitude and settle to the Earths surface. Comets and asteroids are the major sources and the flux, 30,000-40,000 tons/yr, is comparable to the mass of larger meteorites impacting the Earths surface. The sedimentary record suggests that the flux was much higher on the early Earth. The chondritic porous (CP) subset of IDPs together with their larger counterparts, ultracarbonaceous micrometeorites (UCMMs), appear to be unique among known meteoritic materials in that they are composed almost exclusively of anhydrous minerals, some of them contain >> 50% organic carbon by volume as well as the highest abundances of presolar silicate grains including GEMS. D/H and 15N abundances implicate the Oort Cloud or presolar molecular cloud as likely sources of the organic carbon. Prior to atmospheric entry, IDPs and MMs spend 104-105 year lifetimes in solar orbit where their surfaces develop amorphous space weathered rims from exposure to the solar wind (SW). Similar rims are observed on lunar soil grains and on asteroid Itokawa regolith grains. Using valence electron energy-loss spectroscopy (VEELS) we have detected radiolytic water in the rims on IDPs formed by the interaction of solar wind protons with oxygen in silicate minerals. Therefore, IDPs and MMs continuously deliver both water and organics to the earth and other terrestrial planets. The interaction of protons with oxygen-rich minerals to form water is a universal process.

  15. BACODINE/3rd Interplanetary Network burst localization

    International Nuclear Information System (INIS)

    Hurley, K.; Barthelmy, S.; Butterworth, P.; Cline, T.; Sommer, M.; Boer, M.; Niel, M.; Kouveliotou, C.; Fishman, G.; Meegan, C.

    1996-01-01

    Even with only two widely separated spacecraft (Ulysses and GRO), 3rd Interplanetary Network (IPN) localizations can reduce the areas of BATSE error circles by two orders of magnitude. Therefore it is useful to disseminate them as quickly as possible following BATSE bursts. We have implemented a system which transmits the light curves of BACODINE/BATSE bursts directly by e-mail to UC Berkeley immediately after detection. An automatic e-mail parser at Berkeley watches for these notices, determines the Ulysses crossing time window, and initiates a search for the burst data on the JPL computer as they are received. In ideal cases, it is possible to retrieve the Ulysses data within a few hours of a burst, generate an annulus of arrival directions, and e-mail it out to the astronomical community by local nightfall. Human operators remain in this loop, but we are developing a fully automated routine which should remove them, at least for intense events, and reduce turn-around times to an absolute minimum. We explain the current operations, the data types used, and the speed/accuracy tradeoffs

  16. Interplanetary shock induced ring current auroras

    Science.gov (United States)

    Zhang, Yongliang; Paxton, Larry J.; Zheng, Yihua

    2008-01-01

    On 21 January 2005, a fast interplanetary (IP) shock compressed the magnetosphere and caused detached auroras (DA) on the dayside, duskside and nightside ionosphere. The DA were detected by three independent FUV instruments: IMAGE/SI-12, TIMED/GUVI and DMSP/SSUSI. The SI-12 observations show that the dayside detached aurora (DDA) was located between 60° and 68° Mlat and between 06:00 and 15:00 MLT. It lasted for only ˜2 min. Coincident in situ Polar measurements show that sudden bursts of proton EMIC waves (˜2 min) were associated with the DDA. This provides direct evidence of the link between the EMIC waves and the DDA. The DA in the duskside and nightside appeared once the DDA disappeared. GUVI and SSUSI also observed the DA in the duskside and dayside with more details. Ring current simulations show that ˜10 keV protons with sausage-shaped spatial distribution of high anisotropy in flux and temperature were the particle source for the duskside and nightside DA. Compression of the magnetosphere appears to be the driver for both of the DDA and dusk/night DA. The nightside DA was observed for the first time during a sudden commencement. To unify the different terminologies, the detached auroras due to precipitating energetic protons from the ring current are called the ring current auroras.

  17. Optimizing interplanetary trajectories with deep space maneuvers

    Science.gov (United States)

    Navagh, John

    1993-09-01

    Analysis of interplanetary trajectories is a crucial area for both manned and unmanned missions of the Space Exploration Initiative. A deep space maneuver (DSM) can improve a trajectory in much the same way as a planetary swingby. However, instead of using a gravitational field to alter the trajectory, the on-board propulsion system of the spacecraft is used when the vehicle is not near a planet. The purpose is to develop an algorithm to determine where and when to use deep space maneuvers to reduce the cost of a trajectory. The approach taken to solve this problem uses primer vector theory in combination with a non-linear optimizing program to minimize Delta(V). A set of necessary conditions on the primer vector is shown to indicate whether a deep space maneuver will be beneficial. Deep space maneuvers are applied to a round trip mission to Mars to determine their effect on the launch opportunities. Other studies which were performed include cycler trajectories and Mars mission abort scenarios. It was found that the software developed was able to locate quickly DSM's which lower the total Delta(V) on these trajectories.

  18. Modeling user navigation

    NARCIS (Netherlands)

    Herder, E.; Brusilovsky, Peter; Corbett, Albert; de Rosis, Fiorella

    2003-01-01

    For providing users with navigation aids that best serve their needs, user models for adaptive hypermedia should include user navigation patterns. This paper describes elements needed and how these elements can be gathered.

  19. Optical Navigation System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for a flexible navigation system for deep space operations that does not require GPS measurements. The navigation solution is computed using an...

  20. Geo Embedded Navigation

    DEFF Research Database (Denmark)

    Ilsøe, Peer Møller; Kolar, Jan

    2005-01-01

    challenges in this context is to develop a simple and intuitive general purpose navigation mode that will work well for a single planet from outer space to a street level. Such works are missing today. Although the need for global navigation in disaster management is rather conceptual than practical......, introducing a conceptually better navigation mode has positive practical consequences also for applications in the field. By better concept for a navigation mode we mean: The navigation become generally usable around the whole globe regardless location of the viewpoint or level of detailused for the scene...... rendering; the navigation is intuitive for humans; and the navigation is simple by utilizing a single set of straightforward methematical relations. In this text we introduce such global navigation mode, which has been implemented in GRIFINOR system....

  1. Interplanetary Overlay Network Bundle Protocol Implementation

    Science.gov (United States)

    Burleigh, Scott C.

    2011-01-01

    The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

  2. Radar and electronic navigation

    CERN Document Server

    Sonnenberg, G J

    2013-01-01

    Radar and Electronic Navigation, Sixth Edition discusses radar in marine navigation, underwater navigational aids, direction finding, the Decca navigator system, and the Omega system. The book also describes the Loran system for position fixing, the navy navigation satellite system, and the global positioning system (GPS). It reviews the principles, operation, presentations, specifications, and uses of radar. It also describes GPS, a real time position-fixing system in three dimensions (longitude, latitude, altitude), plus velocity information with Universal Time Coordinated (UTC). It is accur

  3. Conceptual Design For Interplanetary Spaceship Discovery

    Science.gov (United States)

    Benton, Mark G.

    2006-01-01

    With the recently revived national interest in Lunar and Mars missions, this design study was undertaken by the author in an attempt to satisfy the long-term space exploration vision of human travel ``to the Moon, Mars, and beyond'' with a single design or family of vehicles. This paper describes a conceptual design for an interplanetary spaceship of the not-to-distant future. It is a design that is outwardly similar to the spaceship Discovery depicted in the novel ``2001 - A Space Odyssey'' and film of the same name. Like its namesake, this spaceship could one day transport a human expedition to explore the moons of Jupiter. This spaceship Discovery is a real engineering design that is capable of being implemented using technologies that are currently at or near the state-of-the-art. The ship's main propulsion and electrical power are provided by bi-modal nuclear thermal rocket engines. Configurations are presented to satisfy four basic Design Reference Missions: (1) a high-energy mission to Jupiter's moon Callisto, (2) a high-energy mission to Mars, (3) a low-energy mission to Mars, and (4) a high-energy mission to the Moon. The spaceship design includes dual, strap-on boosters to enable the high-energy Mars and Jupiter missions. Three conceptual lander designs are presented: (1) Two types of Mars landers that utilize atmospheric and propulsive braking, and (2) a lander for Callisto or Earth's Moon that utilizes only propulsive braking. Spaceship Discovery offers many advantages for human exploration of the Solar System: (1) Nuclear propulsion enables propulsive capture and escape maneuvers at Earth and target planets, eliminating risky aero-capture maneuvers. (2) Strap-on boosters provide robust propulsive energy, enabling flexibility in mission planning, shorter transit times, expanded launch windows, and free-return abort trajectories from Mars. (3) A backup abort propulsion system enables crew aborts at multiple points in the mission. (4) Clustered NTR

  4. Migration of Interplanetary Dust and Comets

    Science.gov (United States)

    Ipatov, S. I.; Mather, J. C.

    Our studies of migration of interplanetary dust and comets were based on the results of integration of the orbital evolution of 15,000 dust particles and 30,000 Jupiter-family comets (JFCs) [1-3]. For asteroidal and cometary particles, the values of the ratio β between the radiation pressure force and the gravitational force varied from 1000 and 1 microns. The probability of a collision of a dust particle started from an asteroid or JFC with the Earth during a lifetime of the particle was maximum at diameter d ˜100 microns. For particles started from asteroids and comet 10P, this maximum probability was ˜0.01. Different studies of migration of dust particles and small bodies testify that the fraction of cometary dust particles of the overall dust population inside Saturn's orbit is considerable and can be dominant: (1) Cometary dust particles produced both inside and outside Jupiter's orbit are needed to explain the observed constant number density of dust particles at 3-18 AU. The number density of migrating trans-Neptunian particles near Jupiter's orbit is smaller by a factor of several than that beyond Saturn's orbit. Only a small fraction of asteroidal particles can get outside Jupiter's orbit. (2) Some (less than 0.1%) JFCs can reach typical near-Earth object orbits and remain there for millions of years. Dynamical lifetimes of most of the former JFCs that have typical near-Earth object orbits are about 106 -109 yr, so during most of these times they were extinct comets. Such former comets could disintegrate and produce a lot of mini-comets and dust. (3) Comparison of the velocities of zodiacal dust particles (velocities of MgI line) based on the distributions of particles over their orbital elements obtained in our runs [3-4] with the velocities obtained at the WHAM observations shows that only asteroidal dust particles cannot explain these observations, and particles produced by comets, including high-eccentricity comets, are needed for such explanation

  5. Safe Laser Beam Propagation for Interplanetary Links

    Science.gov (United States)

    Wilson, Keith E.

    2011-01-01

    Ground-to-space laser uplinks to Earth–orbiting satellites and deep space probes serve both as a beacon and an uplink command channel for deep space probes and Earth-orbiting satellites. An acquisition and tracking point design to support a high bandwidth downlink from a 20-cm optical terminal on an orbiting Mars spacecraft typically calls for 2.5 kW of 1030-nm uplink optical power in 40 micro-radians divergent beams.2 The NOHD (nominal ocular hazard distance) of the 1030nm uplink is in excess of 2E5 km, approximately half the distance to the moon. Recognizing the possible threat of high power laser uplinks to the flying public and to sensitive Earth-orbiting satellites, JPL developed a three-tiered system at its Optical Communications Telescope Laboratory (OCTL) to ensure safe laser beam propagation through navigational and near-Earth space.

  6. Particle acceleration by coronal and interplanetary shock waves

    International Nuclear Information System (INIS)

    Pesses, M.E.

    1982-01-01

    Utilizing many years of observation from deep space and near-earth spacecraft a theoretical understanding has evolved on how ions and electrons are accelerated in interplanetary shock waves. This understanding is now being applied to solar flare-induced shock waves propagating through the solar atmosphere. Such solar flare phenomena as gamma-ray line and neutron emissions, interplanetary energetic electron and ion events, and Type II and moving Type IV radio bursts appear understandable in terms of particle acceleration in shock waves

  7. Capture of interplanetary bodies in geocentric orbits and early lunar ...

    Indian Academy of Sciences (India)

    During the accretion of planets such as Earth,which are formed by collisional accretion of plan-etesimals,the probability of capture of interplanetary bodies in planetocentric orbits is calculated following the approach of Hills (1973)and the -body simulation,using simplectic integration method.The simulation,taking an input ...

  8. A Statistical Study of Interplanetary Type II Bursts: STEREO Observations

    Science.gov (United States)

    Krupar, V.; Eastwood, J. P.; Magdalenic, J.; Gopalswamy, N.; Kruparova, O.; Szabo, A.

    2017-12-01

    Coronal mass ejections (CMEs) are the primary cause of the most severe and disruptive space weather events such as solar energetic particle (SEP) events and geomagnetic storms at Earth. Interplanetary type II bursts are generated via the plasma emission mechanism by energetic electrons accelerated at CME-driven shock waves and hence identify CMEs that potentially cause space weather impact. As CMEs propagate outward from the Sun, radio emissions are generated at progressively at lower frequencies corresponding to a decreasing ambient solar wind plasma density. We have performed a statistical study of 153 interplanetary type II bursts observed by the two STEREO spacecraft between March 2008 and August 2014. These events have been correlated with manually-identified CMEs contained in the Heliospheric Cataloguing, Analysis and Techniques Service (HELCATS) catalogue. Our results confirm that faster CMEs are more likely to produce interplanetary type II radio bursts. We have compared observed frequency drifts with white-light observations to estimate angular deviations of type II burst propagation directions from radial. We have found that interplanetary type II bursts preferably arise from CME flanks. Finally, we discuss a visibility of radio emissions in relation to the CME propagation direction.

  9. Association Between the Solar Wind Speed, Interplanetary Magnetic ...

    Indian Academy of Sciences (India)

    Meena Pokharia

    2017-11-27

    Nov 27, 2017 ... Abstract. The purpose of the present study is to investigate the association of the cosmic ray intensity (CRI) and interplanetary magnetic field (IMF) with high speed solar wind streams (HSSWS) and slow speed solar wind streams (SSSWS) for solar cycle −23 and 24. We have found very interesting and ...

  10. Association Between the Solar Wind Speed, Interplanetary Magnetic ...

    Indian Academy of Sciences (India)

    The purpose of the present study is to investigate the association of the cosmic ray intensity (CRI) and interplanetary magnetic field (IMF) with high speed solar wind streams (HSSWS) and slow speed solar wind streams (SSSWS) for solar cycle −23 and 24. We have found very interesting and adequate results where CRI ...

  11. Effect of solar features and interplanetary parameters on ...

    Indian Academy of Sciences (India)

    Abstract. The dependence of geomagnetic activity on solar features and interplanetary. (IP) parameters is investigated. Sixty-seven intense (−200 nT ≤ Dst < −100 nT) and seventeen superintense (Dst < −200 nT) geomagnetic storms (GMSs) have been studied from January 1996 to April 2006. The number of intense and ...

  12. Automated interplanetary shock detection and its application to Wind observations

    Czech Academy of Sciences Publication Activity Database

    Krupařová, Oksana; Maksimovic, M.; Šafránková, J.; Němeček, Z.; Santolík, Ondřej; Krupař, Vratislav

    2013-01-01

    Roč. 118, č. 8 (2013), 4793–4803 ISSN 2169-9380 R&D Projects: GA ČR(CZ) GAP209/12/2394 Institutional support: RVO:68378289 Keywords : Interplanetary shocks * instruments and techniques Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.440, year: 2013 http://onlinelibrary.wiley.com/doi/10.1002/jgra.50468/abstract

  13. Solar Cycle Variation of Interplanetary Coronal Mass Ejection ...

    Indian Academy of Sciences (India)

    2010-08-25

    Aug 25, 2010 ... Spörer's sunspot law at low latitudes (thus, no 'butterfly diagram'); how- ever, at high latitudes, there may be a poleward motion and an equator- ward motion from the rise to the maximum to the declining phases. Key words. Sun: activity, coronal mass ejections (CMEs). 1. Introduction. Interplanetary coronal ...

  14. Indoor wayfinding and navigation

    CERN Document Server

    2015-01-01

    Due to the widespread use of navigation systems for wayfinding and navigation in the outdoors, researchers have devoted their efforts in recent years to designing navigation systems that can be used indoors. This book is a comprehensive guide to designing and building indoor wayfinding and navigation systems. It covers all types of feasible sensors (for example, Wi-Fi, A-GPS), discussing the level of accuracy, the types of map data needed, the data sources, and the techniques for providing routes and directions within structures.

  15. BIRDY - Interplanetary CubeSat for planetary geodesy of Small Solar System Bodies (SSSB).

    Science.gov (United States)

    Hestroffer, D.; Agnan, M.; Segret, B.; Quinsac, G.; Vannitsen, J.; Rosenblatt, P.; Miau, J. J.

    2017-12-01

    We are developing the Birdy concept of a scientific interplanetary CubeSat, for cruise, or proximity operations around a Small body of the Solar System (asteroid, comet, irregular satellite). The scientific aim is to characterise the body's shape, gravity field, and internal structure through imaging and radio-science techniques. Radio-science is now of common use in planetary science (flybys or orbiters) to derive the mass of the scientific target and possibly higher order terms of its gravity field. Its application to a nano-satellite brings the advantage of enabling low orbits that can get closer to the body's surface, hence increasing the SNR for precise orbit determination (POD), with a fully dedicated instrument. Additionally, it can be applied to two or more satellites, on a leading-trailing trajectory, to improve the gravity field determination. However, the application of this technique to CubeSats in deep space, and inter-satellite link has to be proven. Interplanetary CubeSats need to overcome a few challenges before reaching successfully their deep-space objectives: link to ground-segment, energy supply, protection against radiation, etc. Besides, the Birdy CubeSat — as our basis concept — is designed to be accompanying a mothercraft, and relies partly on the main mission for reaching the target, as well as on data-link with the Earth. However, constraints to the mothercraft needs to be reduced, by having the CubeSat as autonomous as possible. In this respect, propulsion and auto-navigation are key aspects, that we are studying in a Birdy-T engineering model. We envisage a 3U size CubeSat with radio link, object-tracker and imaging function, and autonomous ionic propulsion system. We are considering two case studies for autonomous guidance, navigation and control, with autonomous propulsion: in cruise and in proximity, necessitating ΔV up to 2m/s for a total budget of about 50m/s. In addition to the propulsion, in-flight orbit determination (IFOD

  16. Getting Lost Through Navigation

    DEFF Research Database (Denmark)

    Debus, Michael S.

    2017-01-01

    , ability or process that enables the player’s avatar to traverse the game space (and time). These kinds of movement etc. will be called ‘navigational acts’. Navigation is a constitutional part of ergodic literature (see Aarseth 1997, p. 1) and video game gameplay (see Flynn 2003, p. 8), as the user’s role...... (including AI) (Flynn 2008; Van Driel & Bidarra 2009, p.153; Gazzard 2009, p. 40; Nitsche 2007). While all these studies are concerned with navigation and its connection to certain contexts, what they neglect is a differentiation between specific acts of navigation and their potential influence on the game...... in videogames is a configurational rather than an interpretational one (Eskelinen 2001). Especially in the case of game spaces, navigation appears to be of importance (Wolf 2009; Flynn 2008). Further, it does not only play a crucial role for the games themselves, but also for the experience of the player...

  17. Mobile Robot Navigation

    DEFF Research Database (Denmark)

    Andersen, Jens Christian

    2007-01-01

    validation of the implemented solutions and the ability of the methods to solve real world problems. The amount of software needed by an autonomous robot can be overwhelming. Software reuse and distributed development are therefore important issues. The thesis describes a new component architecture....... The research is now progressing towards autonomous robots which will be able to assist us in our daily life. One of the enabling technologies is navigation, and navigation is the subject of this thesis. Navigation of an autonomous robot is concerned with the ability of the robot to direct itself from....... The perception of these two sensors are utilised by a path planner to allow a number of drive modes, and especially the ability to follow road edges are investigated. The navigation mission is controlled by a script language. The navigation script controls route sequencing, junction detection, junction crossing...

  18. Restricted Navigation Areas - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  19. Cultural ethology as a new approach of interplanetary crew's behavior

    Science.gov (United States)

    Tafforin, Carole; Giner Abati, Francisco

    2017-10-01

    From an evolutionary perspective, during short-term and medium-term orbital flights, human beings developed new spatial and motor behaviors to compensate for the lack of terrestrial gravity. Past space ethological studies have shown adaptive strategies to the tri-dimensional environment, with the goal of optimizing relationships between the astronaut and unusual sensorial-motor conditions. During a long-term interplanetary journey, crewmembers will have to develop new individual and social behaviors to adapt, far from earth, to isolation and confinement and as a result to extreme conditions of living and working together. Recent space psychological studies pointed out that heterogeneity is a feature of interplanetary crews, based on personality, gender mixing, internationality and diversity of backgrounds. Intercultural issues could arise between space voyagers. As a new approach we propose to emphasize the behavioral strategies of human groups' adaptation to this new multicultural dimension of the environment.

  20. The thickness of the interplanetary collisionless shock waves

    International Nuclear Information System (INIS)

    Pinter, S.

    1980-05-01

    The thicknesses of magnetic structures of the interplanetary shock waves related to the upstream solar wind plasma parameters are studied. From this study the following results have been obtained: the measured shock thickness increases for decreasing upstream proton number density and decreases for increasing proton flux energy. The shock thickness strongly depends on the ion plasma β, i.e. for higher values of the β the thickness decreases. (author)

  1. Time-dependent radiation dose estimations during interplanetary space flights

    Science.gov (United States)

    Dobynde, M. I.; Shprits, Y.; Drozdov, A.

    2015-12-01

    Time-dependent radiation dose estimations during interplanetary space flights 1,2Dobynde M.I., 2,3Drozdov A.Y., 2,4Shprits Y.Y.1Skolkovo institute of science and technology, Moscow, Russia 2University of California Los Angeles, Los Angeles, USA 3Lomonosov Moscow State University Skobeltsyn Institute of Nuclear Physics, Moscow, Russia4Massachusetts Institute of Technology, Cambridge, USASpace radiation is the main restriction for long-term interplanetary space missions. It induces degradation of external components and propagates inside providing damage to internal environment. Space radiation particles and induced secondary particle showers can lead to variety of damage to astronauts in short- and long- term perspective. Contribution of two main sources of space radiation- Sun and out-of-heliosphere space varies in time in opposite phase due to the solar activity state. Currently the only habituated mission is the international interplanetary station that flights on the low Earth orbit. Besides station shell astronauts are protected with the Earth magnetosphere- a natural shield that prevents significant damage for all humanity. Current progress in space exploration tends to lead humanity out of magnetosphere bounds. With the current study we make estimations of spacecraft parameters and astronauts damage for long-term interplanetary flights. Applying time dependent model of GCR spectra and data on SEP spectra we show the time dependence of the radiation in a human phantom inside the shielding capsule. We pay attention to the shielding capsule design, looking for an optimal geometry parameters and materials. Different types of particles affect differently on the human providing more or less harm to the tissues. Incident particles provide a large amount of secondary particles while propagating through the shielding capsule. We make an attempt to find an optimal combination of shielding capsule parameters, namely material and thickness, that will effectively decrease

  2. Asynchronous Laser Transponders for Precise Interplanetary Ranging and Time Transfer

    Science.gov (United States)

    Degnan, John J.; Smith, David E. (Technical Monitor)

    2001-01-01

    The feasibility of a two-way asynchronous (i.e. independently firing) interplanetary laser transponder pair, capable of decimeter ranging and subnanosecond time transfer from Earth to a spacecraft anywhere within the inner Solar System, is discussed. In the Introduction, we briefly discuss the current state-of-the-art in Satellite Laser Ranging (SLR) and Lunar Laser Ranging (LLR) which use single-ended range measurements to a passive optical reflector, and the limitations of this approach in ranging beyond the Moon to the planets. In Section 2 of this paper, we describe two types of transponders (echo and asynchronous), introduce the transponder link equation and the concept of "balanced" transponders, describe how range and time can be transferred between terminals, and preview the potential advantages of photon counting asynchronous transponders for interplanetary applications. In Section 3, we discuss and provide mathematical models for the various sources of noise in an interplanetary transponder link including planetary albedo, solar or lunar illumination of the local atmosphere, and laser backscatter off the local atmosphere. In Section 4, we introduce the key engineering elements of an interplanetary laser transponder and develop an operational scenario for the acquisition and tracking of the opposite terminal. In Section 5, we use the theoretical models of th previous sections to perform an Earth-Mars link analysis over a full synodic period of 780 days under the simplifying assumption of coaxial, coplanar, circular orbits. We demonstrate that, using slightly modified versions of existing space and ground based laser systems, an Earth-Mars transponder link is not only feasible but quite robust. We also demonstrate through analysis the advantages and feasibility of compact, low output power (laser ranging system as the Earth terminal. Section 6 provides a summary of the results and some concluding remarks regarding future applications.

  3. Navigation by images

    Directory of Open Access Journals (Sweden)

    Espen Hagen

    1993-07-01

    Full Text Available A new navigation method based on measurements of image tokens and Kalman filtering is presented. An image token is the central projection of a landmark, a point on the terrain surface. This surface being described by an elevation map, a Kalman filter processes the measurements to update estimates of camera position and orientation, and landmarks. The method has been implemented for off-line simulations of aeroplane navigation. Preliminary tests indicate a performance at least comparable to that of satellite navigation systems. The implemented algorithm also seems to have high tolerance against noise and modeling errors.

  4. Inertial navigation without accelerometers

    Science.gov (United States)

    Boehm, M.

    The Kennedy-Thorndike (1932) experiment points to the feasibility of fiber-optic inertial velocimeters, to which state-of-the-art technology could furnish substantial sensitivity and accuracy improvements. Velocimeters of this type would obviate the use of both gyros and accelerometers, and allow inertial navigation to be conducted together with vehicle attitude control, through the derivation of rotation rates from the ratios of the three possible velocimeter pairs. An inertial navigator and reference system based on this approach would probably have both fewer components and simpler algorithms, due to the obviation of the first level of integration in classic inertial navigators.

  5. Relativistic electron dropout echoes induced by interplanetary shocks

    Science.gov (United States)

    Schiller, Q.; Kanekal, S. G.; Boyd, A. J.; Baker, D. N.; Blake, J. B.; Spence, H. E.

    2017-12-01

    Interplanetary shocks that impact Earth's magnetosphere can produce immediate and dramatic responses in the trapped relativistic electron population. One well-studied response is a prompt injection capable of transporting relativistic electrons deep into the magnetosphere and accelerating them to multi-MeV energies. The converse effect, electron dropout echoes, are observations of a sudden dropout of electron fluxes observed after the interplanetary shock arrival. Like the injection echo signatures, dropout echoes can also show clear energy dispersion signals. They are of particular interest because they have only recently been observed and their causal mechanism is not well understood. In the analysis presented here, we show observations of electron drift echo signatures from the Relativistic Electron-Proton Telescope (REPT) and Magnetic Electron and Ion Sensors (MagEIS) onboard NASA's Van Allen Probes mission, which show simultaneous prompt enhancements and dropouts within minutes of the associated with shock impact. We show that the observations associated with both enhancements and dropouts are explained by the inward motion caused by the electric field impulse induced by the interplanetary shock, and either energization to cause the enhancement, or lack of a seed population to cause the dropout.

  6. Sheath-accumulating Propagation of Interplanetary Coronal Mass Ejection

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Takuya; Shibata, Kazunari, E-mail: takahasi@kusastro.kyoto-u.ac.jp [Kwasan and Hida Observatories, Kyoto University, Yamashina, Kyoto 607–8471 (Japan)

    2017-03-10

    Fast interplanetary coronal mass ejections (ICMEs) are the drivers of strong space weather storms such as solar energetic particle events and geomagnetic storms. The connection between the space-weather-impacting solar wind disturbances associated with fast ICMEs at Earth and the characteristics of causative energetic CMEs observed near the Sun is a key question in the study of space weather storms, as well as in the development of practical space weather prediction. Such shock-driving fast ICMEs usually expand at supersonic speeds during the propagation, resulting in the continuous accumulation of shocked sheath plasma ahead. In this paper, we propose a “sheath-accumulating propagation” (SAP) model that describes the coevolution of the interplanetary sheath and decelerating ICME ejecta by taking into account the process of upstream solar wind plasma accumulation within the sheath region. Based on the SAP model, we discuss (1) ICME deceleration characteristics; (2) the fundamental condition for fast ICMEs at Earth; (3) the thickness of interplanetary sheaths; (4) arrival time prediction; and (5) the super-intense geomagnetic storms associated with huge solar flares. We quantitatively show that not only the speed but also the mass of the CME are crucial for discussing the above five points. The similarities and differences between the SAP model, the drag-based model, and the“snow-plow” model proposed by Tappin are also discussed.

  7. Division F Commission 22: Meteors, Meteorites, and Interplanetary Dust

    Science.gov (United States)

    Jenniskens, Peter; Borovička, Jiří; Watanabe, Jun-Ichi; Jopek, Tadeusz; Abe, Shinsuke; Consolmagno, Guy J.; Ishiguro, Masateru; Janches, Diego; Ryabova, Galina O.; Vaubaillon, Jérémie; Zhu, Jin

    2016-04-01

    Commission 22 (Meteors, Meteorites and Interplanetary Dust) was established at the first IAU General Assembly held in Rome in 1922, with William Frederick Denning as its first President. Denning was an accountant by profession, but as an amateur astronomer he contributed extensively to meteor science. Commission 22 thus established a pattern that has continued to this day that non-professional astronomers were welcomed and valued and could play a significant role in its affairs. The field of meteors, meteorites and interplanetary dust has played a disproportional role in the astronomical perception of the general public through the majestic displays of our annual meteor showers. Those in the field deployed many techniques uncommon in other fields of astronomy, studying the ``vermin of space'', the small solid bodies that pervade interplanetary space and impact Earth's atmosphere, the surface of the Moon, and that of our satellites in orbit. Over time, the field has tackled a wide array of problems, from predicting the encounter with meteoroid streams, to the origin of our meteorites and the nature of the zodiacal cloud. Commission 22 has played an important role in organizing the field through dedicated meetings, a data centre, and working groups that developed professional-amateur relationships and that organized the nomenclature of meteor showers. The contribution of Commission 22 to the field is perhaps most readily seen in the work of the presidents that followed in the footsteps of Denning.

  8. A sheet-current approach to coronal-interplanetary modeling

    International Nuclear Information System (INIS)

    Yeh, T.; Pneuman, G.W.

    1977-01-01

    The most pertinent effect of the currents in the coronal-interplanetary space is their alteration of the magnetic topology to form configurations of open field lines. The important currents seem to be those in the neighborhoods of the interfaces between closed and open field lines or between oppositely directed open field lines in the coronal helmet-streamer structures. Thus, the coronal-interplanetary space may be regarded as being partitioned by current-sheets into several piecewise current-free regions. These current sheets overlie the photospheric neutral lines, where the vertical component of the magnetic field reverses its polarity on the solar surface. But, their locations and strengths are determined by force balance between the magnetic field and the gas pressure in the coronal-interplanetary space. Since the pressure depends on the flow velocity of the solar wind and the solar wind channels along magnetic flux tubes, there is a strong magnetohydrodynamic coupling between the magnetic field and the solar wind. The sheet-current approach presented in this paper seems to be a reasonable way to account for this complicated interaction. (Auth.)

  9. The dynamics of solar plasma events and their interplanetary consequences

    Science.gov (United States)

    Kaushik, Subhash Chandra; Sharma, Giriraj

    2015-07-01

    In the present study we have analyzed the interplanetary plasma / field parameter, which have initiated the complex nature intense and highly geo-effective events in the magnetosphere. It is believed that Solar wind velocity V. interplanetary magnetic field (IMF) B and Bz are the crucial drivers of these activities. However, sometimes strong geomagnetic disturbance is associated with the interaction between slow and fast solar wind streams originating from coronal holes leads to create co-rotating plasma interaction region (CIR). Thus the dynamics of the magnetospheric plasma configuration is the reflection of measured solar wind and interplanetary magnetic field (IMF) conditions. While the magnetospheric plasma anomalies are generally represented by geomagnetic storms and sudden ionosphere disturbance (SIDs). The study considers 220 geomagnetic storms associated with disturbance storm time (Dst) decrease of more than -50 nT to -300 nT, observed during solar cycle 23 and the ascending phase of solar cycle 24. These have been analyzed and studied statistically. The spacecraft data acquired by space satellites and those provided by World Data Center (WDC) - A and geomagnetic stations data from WDC- C, Kyoto are utilized in the study. It is observed that the yearly occurrences of geomagnetic storm are strongly correlated with sunspot cycle, however we have not found any significant correlation between the maximum and minimum phase of solar cycle. It is also inferred from the results that solar cycle-23 was remarkable for occurrence of intense geomagnetic storms during its descending phase.

  10. Dynamics of the Solar Plasma Events and Their Interplanetary Consequences

    Science.gov (United States)

    Kaushik, Subhash Chandra

    2016-07-01

    In the present study we have analyzed the interplanetary plasma / field parameter, which have initiated the complex nature intense and highly geo-effective events in the magnetosphere. It is believed that Solar wind velocity V. interplanetary magnetic field (IMF) B and Bz are the crucial drivers of these activities. However, sometimes strong geomagnetic disturbance is associated with the interaction between slow and fast solar wind originating from coronal holes leads to create co-rotating plasma interaction region (CIR). Thus the dynamics of the magnetospheric plasma configuration is the reflection of measured solar wind and interplanetary magnetic field (IMF) conditions. While the magnetospheric plasma anomalies are generally represented by geomagnetic storms and sudden ionosphere disturbance (SIDs). The study considers geomagnetic storms associated with disturbance storm time (Dst) decreases of more than -50 nT to -300 nT, observed during solar cycle 23 and the ascending phase of solar cycle 24. These have been analyzed and studied statistically. The spacecraft data those provided by SOHO, ACE and geomagnetic stations like WDC-Kyoto are utilized in the study. It is observed that the yearly occurrences of geomagnetic storm are strongly correlated with 11-year sunspot cycle, but no significant correlation between the maximum and minimum phase of solar cycle have been found. It is also found that solar cycle-23 is remarkable for occurrence of intense geomagnetic storms during its declining phase. The detailed results are discussed in this paper.

  11. Navigating Distributed Services

    DEFF Research Database (Denmark)

    Beute, Berco

    2002-01-01

    of devices used to access information on the Internet.The focal point of the thesis is an initial exploration of the effects of the trends onusers as they navigate the virtual environment of distributed documents and services.To begin the thesis uses scenarios as a heuristic device to identify and analyse......This thesis explores the impact of three current trends which, when taken together, arefundamentally changing the way in which the task of navigating virtual environmentsis accomplished. The first concerns the changeover from a situation in which all dataand functionality reside locally to the user...... themain effects of the trends. This is followed by an exploration of theory of navigationInformation Spaces, which is in turn followed by an overview of theories, and the stateof the art in navigating distributed services. These explorations of both theory andpractice resulted in a large number of topics...

  12. Tinnitus Patient Navigator

    Science.gov (United States)

    ... Cure About Us Initiatives News & Events Professional Resources Tinnitus Patient Navigator Want to get started on the ... unique and may require a different treatment workflow. Tinnitus Health-Care Providers If you, or someone you ...

  13. Visual Guided Navigation

    National Research Council Canada - National Science Library

    Banks, Martin

    1999-01-01

    .... Similarly, the problem of visual navigation is the recovery of an observer's self-motion with respect to the environment from the moving pattern of light reaching the eyes and the complex of extra...

  14. Semiotic resources for navigation

    DEFF Research Database (Denmark)

    Due, Brian Lystgaard; Lange, Simon Bierring

    2018-01-01

    This paper describes two typical semiotic resources blind people use when navigating in urban areas. Everyone makes use of a variety of interpretive semiotic resources and senses when navigating. For sighted individuals, this especially involves sight. Blind people, however, must rely on everything...... else than sight, thereby substituting sight with other modalities and distributing the navigational work to other semiotic resources. Based on a large corpus of fieldwork among blind people in Denmark, undertaking observations, interviews, and video recordings of their naturally occurring practices...... of walking and navigating, this paper shows how two prototypical types of semiotic resources function as helpful cognitive extensions: the guide dog and the white cane. This paper takes its theoretical and methodological perspective from EMCA multimodal interaction analysis....

  15. Navigation with Atom Interferometers

    Science.gov (United States)

    2017-03-20

    Navigation with Atom Interferometers Mary F. Locke and Frank A. Narducci Avionics Department Naval Air Systems Command Patuxent River, Md...20670 Abstract: In this article, we review the basic physics of an atom interferometer. We highlight the usefulness of atom interferometers for...inertial navigation due to their high phase sensitivity to both linear acceleration and angular rotation, but also the drawback that a single atom

  16. Navigational strategies and models

    Directory of Open Access Journals (Sweden)

    T. Rodrigo

    2002-01-01

    Full Text Available Many scientists are interested in the different mechanisms and strategies that animals use to navigate. This paper reviews a series of studies and models about the navigational strategies that animals can use to move from one place to another. Studies of long-distance navigation have mainly been focused on how animals are able to maintain a certain orientation across a distance of hundreds of kilometers. These studies have shown the great variety of sources of information that animals can use to orientate themselves, as well as their redundancy. But, for successful navigation to occur, animals not only have to know how to orientate themselves, they also have to know which direction they should be orientated and for how long. Direction and duration have mainly been studied in short-distance navigation. These studies have shown that animals can use a variety of strategies to locate a given goal. Whether an animal uses a specific strategy will depend on its sensory capabilities and also on the conditions imposed by the environment.

  17. Solar events and their influence on the interplanetary medium

    Science.gov (United States)

    Joselyn, Jo Ann

    The Workshop on Solar Events and Their Influence on the Interplanetary Medium very successfully met its goal “to foster interactions among colleagues, leading to an improved understanding of the unified relationship between solar events and interplanetary disturbances.” Organized by the National Oceanic and Atmospheric Administration Space Environment Laboratory and funded by the national Aeronautics and Space Administration (NASA) Solar Maximum Mission Principal Investigators and the Space Environment Laboratory, this meeting was held held September 8—11, 1986, in Estes Park, Colo. A total of 94 scientists, including representatives from Argentina, Germany, Japan, France, Scotland, England, Australia, Poland, Israel, Greece, China and the United States attended. A novel meeting schedule was adopted, with no formal presentations other than a keynote address by Rainer Schwenn of the Max Planck Institut fur Aeronomie (Federal republic of Germany), entitled “Transients on the Sun and Their Effects on the Interplanetary Medium: An Interdisciplinary Challenge” a Gordon A. Newkirk Memorial talk on “Early History of the Coronagraph” by John Eddy of the University Corporation for Atmospheric Research Office of Interdisciplinary Earth Studies (Boulder, Colo.); and introductory and summary statements by working group leaders. Instead, there were three working groups, which met either independently or with one of the other groups according to a prearranged plan. Suggested roundtable discussion topics were distributed in advance to the members of each group, but primarily, each group was expected to think of questions for the other groups and respond to requests for information from them. As may be expected, for some topics there was group consensus. Other topics were contentious.

  18. Geometrical Relationship Between Interplanetary Flux Ropes and Their Solar Sources

    Science.gov (United States)

    Marubashi, K.; Akiyama, S.; Yashiro, S.; Gopalswamy, N.; Cho, K.-S.; Park, Y.-D.

    2015-05-01

    We investigated the physical connection between interplanetary flux ropes (IFRs) near Earth and coronal mass ejections (CMEs) by comparing the magnetic field structures of IFRs and CME source regions. The analysis is based on the list of 54 pairs of ICMEs (interplanetary coronal mass ejections) and CMEs that are taken to be the most probable solar source events. We first attempted to identify the flux rope structure in each of the 54 ICMEs by fitting models with a cylinder and torus magnetic field geometry, both with a force-free field structure. This analysis determined the possible geometries of the identified flux ropes. Then we compared the flux rope geometries with the magnetic field structure of the solar source regions. We obtained the following results: (1) Flux rope structures are seen in 51 ICMEs out of the 54. The result implies that all ICMEs have an intrinsic flux rope structure, if the three exceptional cases are attributed to unfavorable observation conditions. (2) It is possible to find flux rope geometries with the main axis orientation close to the orientation of the magnetic polarity inversion line (PIL) in the solar source regions, the differences being less than 25°. (3) The helicity sign of an IFR is strongly controlled by the location of the solar source: flux ropes with positive (negative) helicity are associated with sources in the southern (northern) hemisphere (six exceptions were found). (4) Over two-thirds of the sources in the northern hemisphere are concentrated along PILs with orientations of 45° ± 30° (measured clockwise from the east), and over two-thirds in the southern hemisphere along PILs with orientations of 135° ± 30°, both corresponding to the Hale boundaries. These results strongly support the idea that a flux rope with the main axis parallel to the PIL erupts in a CME and that the erupted flux rope propagates through the interplanetary space with its orientation maintained and is observed as an IFR.

  19. Capture of interplanetary and interstellar dust by the jovian magnetosphere.

    Science.gov (United States)

    Colwell, J E; Horányi, M; Grün, E

    1998-04-03

    Interplanetary and interstellar dust grains entering Jupiter's magnetosphere form a detectable diffuse faint ring of exogenic material. This ring is composed of particles in the size range of 0. 5 to 1.5 micrometers on retrograde and prograde orbits in a 4:1 ratio, with semimajor axes 3 jovian radii, eccentricities 0. 1 < e < 0.3, and inclinations i less, similar 20 degrees or i greater, similar 160 degrees. The size range and the orbital characteristics are consistent with in situ detections of micrometer-sized grains by the Galileo dust detector, and the measured rates match the number densities predicted from numerical trajectory integrations.

  20. INTERPLANETARY NETWORK LOCALIZATIONS OF KONUS SHORT GAMMA-RAY BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Pal' shin, V. D.; Svinkin, D. S.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D.; Mazets, E. P.; Oleynik, P. P.; Ulanov, M. V. [Ioffe Physical Technical Institute, St. Petersburg, 194021 (Russian Federation); Hurley, K. [Space Sciences Laboratory, University of California, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Cline, T.; Trombka, J.; McClanahan, T. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Boynton, W.; Fellows, C.; Harshman, K., E-mail: val@mail.ioffe.ru [Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721 (United States); and others

    2013-08-15

    Between the launch of the Global Geospace Science Wind spacecraft in 1994 November and the end of 2010, the Konus-Wind experiment detected 296 short-duration gamma-ray bursts (including 23 bursts which can be classified as short bursts with extended emission). During this period, the Interplanetary Network (IPN) consisted of up to 11 spacecraft, and using triangulation, the localizations of 271 bursts were obtained. We present the most comprehensive IPN localization data on these events. The short burst detection rate, {approx}18 yr{sup -1}, exceeds that of many individual experiments.

  1. Velocity of interplanetary shock waves according to radioastronomical data

    International Nuclear Information System (INIS)

    Vlasov, V.I.

    1988-01-01

    Velocities of 34 interplanetary shock waves are estimated by the method of radioastronomical cartography of scintillation indices of cosmic radiosources. The velocity of shock waves within the limits of approximately 0.2-1.2 a.e. is shown to decrease as far as they are far from the Sun at a distance equalling 1/r α , where 0.25 < or approx. α ≤ 1. In this case the degree of shock wave slowing-down dependences on their initial velocity; the velocity radial gradient is approximately proportional to the square of the shock wave initial velocity

  2. The Interplanetary Network I: From the Past to the Future

    Science.gov (United States)

    Cline, T. L.; Hurley, K.; Laros, J.; Mazets, E.; Golenetskii, S.; Trombka, J.; Feroci, M.; Frontera, F.

    2000-10-01

    Interplanetary spacecraft have been used with orbiting satellites to precisely localize gamma ray transients for nearly 25 years, making possible both early GRB and SGR discoveries and recent afterglow observations. This technique, always subject to the vagaries of circumstance, was maintained by creative experiment modifications from seeming space piracy to the NEAR in-flight software change that made possible the present fully long-baseline network. We review the anecdotal history of the IPN, and outline future IPN possibilities when HETE-2, INTEGRAL, Mars 2001, AGILE, Swift, GLAST and the ISS may be involved.

  3. Interplanetary dust fluxes, solar and galactic cosmic rays

    International Nuclear Information System (INIS)

    Bel'skij, S.A.

    1978-01-01

    The role of dust fluxes in cosmic ray (CR) propagation in the interplanetary space is investigated. Global effects arising in the interaction of CR with magnetic and electric fields of a sporadic meteor cloud or of all meteor fluxes as a whole are discussed. The local effects arising in the interaction of CR with magnetic and electric fields of separate meteor fluxes are also considered. It is shown that an increase in the CR intensity during the maximum activity of meteor fluxes confirms the supposition on the CR acceleration in electric fields of meteor fluxes

  4. Radiation protection for human interplanetary spaceflight and planetary surface operations

    Energy Technology Data Exchange (ETDEWEB)

    Clark, B.C. [Armed Forces Radiobiology Research Inst., Bethesda, MD (United States)]|[DLR Inst. of Aerospace Medicine, Cologne (Germany)]|[NASA, Goddard Space Flight Center, Greenbelt, MD (United States)

    1993-12-31

    Radiation protection issues are reviewed for five categories of radiation exposure during human missions to the moon and Mars: trapped radiation belts, galactic cosmic rays, solar flare particle events, planetary surface emissions, and on-board radiation sources. Relative hazards are dependent upon spacecraft and vehicle configurations, flight trajectories, human susceptibility, shielding effectiveness, monitoring and warning systems, and other factors. Crew cabins, interplanetary mission modules, surface habitats, planetary rovers, and extravehicular mobility units (spacesuits) provide various degrees of protection. Countermeasures that may be taken are reviewed relative to added complexity and risks that they could entail, with suggestions for future research and analysis.

  5. Navigating in higher education

    DEFF Research Database (Denmark)

    Thingholm, Hanne Balsby; Reimer, David; Keiding, Tina Bering

    Denne rapport er skrevet på baggrund af spørgeskemaundersøgelsen – Navigating in Higher Education (NiHE) – der rummer besvarelser fra 1410 bachelorstuderende og 283 undervisere fordelt på ni uddannelser fra Aarhus Universitet: Uddannelsesvidenskab, Historie, Nordisk sprog og litteratur, Informati......Denne rapport er skrevet på baggrund af spørgeskemaundersøgelsen – Navigating in Higher Education (NiHE) – der rummer besvarelser fra 1410 bachelorstuderende og 283 undervisere fordelt på ni uddannelser fra Aarhus Universitet: Uddannelsesvidenskab, Historie, Nordisk sprog og litteratur...

  6. Helioseismology with Seismometers: II Coherence with the Interplanetary Magnetic Field

    Science.gov (United States)

    Thomson, David J.; Vernon, Frank L.

    2015-04-01

    Since the discovery of seismic "hum'' in 1998 unexpected lines have been observed in terrestrial seismology.In this talk we give further evidence that these lines originate as normal modes of the Sun. Frequencies observed in terrestrial seismic and geomagnetic data are often split by multiples of a cycle/day and, unexpectedly, by multiples of one-half cycle per sidereal day.There is coherence between the interplanetary magnetic field (IMF) at ACE (located at L_1) and terrestrial geomagnetic and seismic data. There are slight frequency offsets between colocated geomagnetic and seismic data similar to those observed in normal modes excited by earthquakes. These have been attributed to dispersion from large-scale structure in the Earth.Both the splitting and coherence with the IMF give further confirmation that solar modes propagatethrough interplanetary space and are sufficiently strong to literally shake the Earth. This gives another method to detect and possibly identify solar gravity and low--frequency P-modes.

  7. First Taste of Hot Channel in Interplanetary Space

    Science.gov (United States)

    Song, H. Q.; Zhang, J.; Chen, Y.; Cheng, X.; Li, G.; Wang, Y. M.

    2015-04-01

    A hot channel (HC) is a high temperature (˜10 MK) structure in the inner corona first revealed by the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. Eruptions of HCs are often associated with flares and coronal mass ejections (CMEs). Results of previous studies have suggested that an HC is a good proxy for a magnetic flux rope (MFR) in the inner corona as well as another well known MFR candidate, the prominence-cavity structure, which has a normal coronal temperature (˜1-2 MK). In this paper, we report a high temperature structure (HTS, ˜1.5 MK) contained in an interplanetary CME induced by an HC eruption. According to the observations of bidirectional electrons, high temperature and density, strong magnetic field, and its association with the shock, sheath, and plasma pile-up region, we suggest that the HTS is the interplanetary counterpart of the HC. The scale of the measured HTS is around 14 R ⊙ , and it maintained a much higher temperature than the background solar wind even at 1 AU. It is significantly different from the typical magnetic clouds, which usually have a much lower temperature. Our study suggests that the existence of a corotating interaction region ahead of the HC formed a magnetic container to inhibit expansion of the HC and cool it down to a low temperature.

  8. Counterstreaming electrons in small interplanetary magnetic flux ropes

    Science.gov (United States)

    Feng, H. Q.; Zhao, G. Q.; Wang, J. M.

    2015-12-01

    Small interplanetary magnetic flux ropes (SIMFRs) are commonly observed by spacecraft at 1 AU, and their origin still remains disputed. We investigated the counterstreaming suprathermal electron (CSE) signatures of 106 SIMFRs measured by Wind during 1995-2005. We found that 79 (75%) of the 106 flux ropes contain CSEs, and the percentages of counterstreaming vary from 8% to 98%, with a mean value of 51%. CSEs are often observed in magnetic clouds (MCs), and this indicates these MCs are still attached to the Sun at both ends. CSEs are also related to heliospheric current sheets (HCSs) and the Earth's bow shock. We divided the SIMFRs into two categories: The first category is far from HCSs, and the second category is in the vicinity of HCSs. The first category has 57 SIMFRs, and only 7 of 57 ropes have no CSEs. This ratio is similar to that of MCs. The second category has 49 SIMFRs; however, 20 of the 49 events have no CSEs. This ratio is larger than that of MCs. These two categories have different origins. One category originates from the solar corona, and most ropes are still connected to the Sun at both ends. The other category is formed near HCSs in the interplanetary space.

  9. The topology of intrasector reversals of the interplanetary magnetic field

    Science.gov (United States)

    Kahler, S. W.; Crooker, N. U.; Gosling, J. T.

    1996-11-01

    A technique has been developed recently to determine the polarities of interplanetary magnetic fields relative to their origins at the Sun by comparing energetic electron flow directions with local magnetic field directions. Here we use heat flux electrons from the Los Alamos National Laboratory (LANL) plasma detector on the ISEE 3 spacecraft to determine the field polarities. We examine periods within well-defined magnetic sectors when the field directions appear to be reversed from the normal spiral direction of the sector. About half of these intrasector field reversals (IFRs) are cases in which the polarities match those of the surrounding sectors, indicating that those fields have been folded back toward the Sun. The more interesting cases are those with polarity reversals. We find no clear cases of isolated reverse polarity fields, which suggests that islands of reverse polarity in the solar source dipole field probably do not exist. The IFRs with polarity reversals are strongly associated with periods of bidirectional electron flows, suggesting that those fields occur only in conjunction with closed fields. We propose that both those IFRs and the bidirectional flows are signatures of coronal mass ejections (CMEs). In that case, many interplanetary CMEs are larger and more complex than previously thought, consisting of both open and closed field components.

  10. North-South asymmetry of interplanetary plasma and solar parameters

    International Nuclear Information System (INIS)

    El-Borie, M. A.

    2001-01-01

    Data of interplanetary plasma (field magnitude, solar wind speed, ion plasma density and temperature) and solar parameters (sunspot number, solar radio flux, and geomagnetic index) over the period 1965-1991, have been used to examine the asymmetry between the solar field north and south of the heliospheric current sheet (HCS). The dependence of N-S asymmetry of field magnitude (B) upon the interplanetary solar polarities is statistically insignificant. There is no clear indication for the presence of N-S asymmetry in the grand-average field magnitude over the solar cycles. During the period 1981-89 (qA<0; negative solar polarity state), the solar plasma was more dense and cooler south of the HCS than north of it. The solar flux component of toward field vector is larger in magnitude than those of away field vector during the qA<0 epoch, and no asymmetry observed in the qA<0 epoch. Furthermore, the sign of the N-S asymmetry in the solar activity depends positively upon the solar polarity state. In addition, it was studied the N-S asymmetry of solar parameters near the HCS, throughout the periods of northern and southern hemispheres were more active than the other. Some asymmetries (with respect to the HCS) in plasma parameters existed during the periods of southern hemisphere predominance

  11. Navigating on handheld displays: Dynamic versus Static Keyhole Navigation

    NARCIS (Netherlands)

    Mehra, S.; Werkhoven, P.; Worring, M.

    2006-01-01

    Handheld displays leave little space for the visualization and navigation of spatial layouts representing rich information spaces. The most common navigation method for handheld displays is static peephole navigation: The peephole is static and we move the spatial layout behind it (scrolling). A

  12. Navigating between the Dimensions

    Science.gov (United States)

    Fleron, Julian F.; Ecke, Volker

    2011-01-01

    Generations have been inspired by Edwin A. Abbott's profound tour of the dimensions in his novella "Flatland: A Romance of Many Dimensions" (1884). This well-known satire is the story of a flat land inhabited by geometric shapes trying to navigate the subtleties of their geometric, social, and political positions. In this article, the authors…

  13. Navigating ‘riskscapes’

    DEFF Research Database (Denmark)

    Gee, Stephanie; Skovdal, Morten

    2017-01-01

    This paper draws on interview data to examine how international health care workers navigated risk during the unprecedented Ebola outbreak in West Africa. It identifies the importance of place in risk perception, including how different spatial localities give rise to different feelings of threat...

  14. Optical Navigation System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is for a flexible navigation system for deep space operations that does not require GPS measurements. The navigation solution is computed using an...

  15. Inland Electronic Navigational Charts (IENC)

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — These Inland Electronic Navigational Charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  16. Exospheric and interplanetary hydrogen sensing from a translunar CubeSat platform by the Tomographic Hydrogen Emission Observatory (THEO)

    Science.gov (United States)

    Waldrop, L.; Sample, J. G.; Doe, R.; Noto, J.; Walsh, B.; Kamalabadi, F.; Mierkiewicz, E. J.; Kerr, R. B.; Immel, T. J.

    2015-12-01

    The evaporation of neutral hydrogen (H) atmospheres into interplanetary space is a near-ubiquitous process in the universe that can be strongly perturbed by charge exchange coupling with ambient ions, influencing atmospheric evolution as well as the dissipation of plasma energy. Space-based observation of solar ultraviolet (UV) radiation scattered by H atoms is a powerful means to infer the underlying exospheric density distribution and thus unravel the competing effects of thermal and non-thermal processes on H energization and escape. Numerous past and present NASA missions have obtained measurements of terrestrial H emission at 121.6 nm (Lyman alpha) from earth-orbiting satellite platforms. However, their separate targeting of either the optically thick emission in the lower exosphere or the optically thin emission in the outer exosphere, together with their lack of independent measurement of the interplanetary emission that constitutes a significant background contamination, renders such data insufficient to advance exospheric science beyond current understanding. Here, we describe a new nano-satellite mission concept for exospheric H investigation that overcomes these historical measurement limitations. The mission, known as the Tomographic Hydrogen Emission Observatory (THEO), is designed to provide 3-D photometric measurements of terrestrial H Lyman alpha emission from a highly autonomous, three-axis-stabilized, 6U CubeSat platform along a trans-lunar trajectory that is ideal for the unambiguous estimation of H density from the exobase to the magnetopause and beyond. In particular, we will describe the feasibility of meeting operational challenges associated with satellite navigation and communication at such large distances.

  17. Positive and negative sudden impulses caused by fast forward and reverse interplanetary shocks

    Energy Technology Data Exchange (ETDEWEB)

    Andrioli, Vania Fatima; Savian, Jairo Francisco, E-mail: vaniafatima@gmail.com, E-mail: savian@lacesm.ufsm.br [Space Science Laboratory of Santa Maria - LACESM/CT - UFSM, Universidade Federal de Santa Maria - UFSM, Centro Tecnologico, Santa Maria, RS (Brazil); Echer, Ezequiel, E-mail: eecher@dge.inpe.br [National Institute for Space Research - INPE - MCT, Sao Jose dos Campos, SP (Brazil); Schuch, Nelson Jorge, E-mail: njschuch@lacesm.ufsm.br [Southern Regional Space Research Center - CRSPE/INPE - MCT, Universidade Federal de Santa Maria - UFSM, Santa Maria, RS (Brazil)

    2007-07-01

    Fast forward interplanetary shocks (FFS) are characterized by positive jump in all interplanetary plasma parameters (solar wind speed, temperature and density) and interplanetary magnetic field. However the fast reverse interplanetary shocks (FRS) are characterized by negative jump in all mentioned parameters except solar wind speed. Observations show that FFS cause positive sudden impulses (SI) while FRS cause negative SI in the H-component of the geomagnetic field. In this work we investigate the SI caused by interplanetary shocks. We use the observed plasma parameters, upstream and downstream, to calculate the variation of dynamic pressure. We observe that the SI amplitude is larger for positive SI than for negative ones, as a consequence of the fact that FFS have larger dynamic pressure variations as compared to FRS. (author)

  18. Terrain-Adaptive Navigation Architecture

    Science.gov (United States)

    Helmick, Daniel M.; Angelova, Anelia; Matthies, Larry H.; Helmick, Daniel M.

    2008-01-01

    A navigation system designed for a Mars rover has been designed to deal with rough terrain and/or potential slip when evaluating and executing paths. The system also can be used for any off-road, autonomous vehicles. The system enables vehicles to autonomously navigate different terrain challenges including dry river channel systems, putative shorelines, and gullies emanating from canyon walls. Several of the technologies within this innovation increase the navigation system s capabilities compared to earlier rover navigation algorithms.

  19. Coastal Piloting & Charting: Navigation 101.

    Science.gov (United States)

    Osinski, Alison

    This curriculum guide for a beginning course on marine navigation describes marine navigation (the art of and science of determining position of a ship and its movement from one position to another in order to keep track of where the ship is and where it is going) and defines dead reckoning, piloting, electronic navigation, and celestial…

  20. Architectural Design for a Mars Communications and Navigation Orbital Infrastructure

    Science.gov (United States)

    Ceasrone R. J.; Hastrup, R. C.; Bell, D. J.; Roncoli, R. B.; Nelson, K.

    1999-01-01

    The planet Mars has become the focus of an intensive series of missions that span decades of time, a wide array of international agencies and an evolution from robotics to humans. The number of missions to Mars at any one time, and over a period of time, is unprecedented in the annals of space exploration. To meet the operational needs of this exploratory fleet will require the implementation of new architectural concepts for communications and navigation. To this end, NASA's Jet Propulsion Laboratory has begun to define and develop a Mars communications and navigation orbital infrastructure. This architecture will make extensive use of assets at Mars, as well as use of traditional Earth-based assets, such as the Deep Space Network, DSN. Indeed, the total system can be thought of as an extension of DSN nodes and services to the Mars in-situ region. The concept has been likened to the beginnings of an interplanetary Internet that will bring the exploration of Mars right into our living rooms. The paper will begin with a high-level overview of the concept for the Mars communications and navigation infrastructure. Next, the mission requirements will be presented. These will include the relatively near-term needs of robotic landers, rovers, ascent vehicles, balloons, airplanes, and possibly orbiting, arriving and departing spacecraft. Requirements envisioned for the human exploration of Mars will also be described. The important Mars orbit design trades on telecommunications and navigation capabilities will be summarized, and the baseline infrastructure will be described. A roadmap of NASA's plan to evolve this infrastructure over time will be shown. Finally, launch considerations and delivery to Mars will be briefly treated.

  1. Control algorithms for autonomous robot navigation

    International Nuclear Information System (INIS)

    Jorgensen, C.C.

    1985-01-01

    This paper examines control algorithm requirements for autonomous robot navigation outside laboratory environments. Three aspects of navigation are considered: navigation control in explored terrain, environment interactions with robot sensors, and navigation control in unanticipated situations. Major navigation methods are presented and relevance of traditional human learning theory is discussed. A new navigation technique linking graph theory and incidental learning is introduced

  2. Control algorithms for autonomous robot navigation

    Energy Technology Data Exchange (ETDEWEB)

    Jorgensen, C.C.

    1985-09-20

    This paper examines control algorithm requirements for autonomous robot navigation outside laboratory environments. Three aspects of navigation are considered: navigation control in explored terrain, environment interactions with robot sensors, and navigation control in unanticipated situations. Major navigation methods are presented and relevance of traditional human learning theory is discussed. A new navigation technique linking graph theory and incidental learning is introduced.

  3. The Interplanetary Network Response to LIGO GW150914

    Science.gov (United States)

    Hurley, K.; Svinkin, D. S.; Aptekar, R.L.; Golenetskii, S. V.; Frederiks, D. D.; Boynton, W.; Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; hide

    2016-01-01

    We have performed a blind search for a gamma-ray transient of arbitrary duration and energy spectrum around the time of the LIGO gravitational-wave event GW150914 with the six-spacecraft interplanetary network (IPN). Four gamma-ray bursts were detected between 30 hr prior to the event and 6.1 hr after it, but none could convincingly be associated with GW150914. No other transients were detected down to limiting 15-150 keV fluences of roughly 5 x 10(exp -8) -5 x 10(exp -7) erg cm(exp -2). We discuss the search strategies and temporal coverage of the IPN on the day of the event and compare the spatial coverage to the region where GW150914 originated. We also report the negative result of a targeted search for the Fermi-GBM event reported in conjunction with GW150914.

  4. THE INTERPLANETARY NETWORK RESPONSE TO LIGO GW150914

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, K. [University of California, Berkeley, Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); Svinkin, D. S.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D. [Ioffe Physical Technical Institute, Politekhnicheskaya 26, St. Petersburg 194021 (Russian Federation); Boynton, W. [University of Arizona, Department of Planetary Sciences, Tucson, AZ 85721 (United States); Mitrofanov, I. G.; Golovin, D. V.; Kozyrev, A. S.; Litvak, M. L.; Sanin, A. B. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Rau, A.; Kienlin, A. von; Zhang, X. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, Postfach 1312, Garching, D-85748 Germany (Germany); Connaughton, V.; Meegan, C. [University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Cline, T.; Gehrels, N., E-mail: khurley@ssl.berkeley.edu [NASA Goddard Space Flight Center, Code 661, Greenbelt, MD 20771 (United States)

    2016-09-20

    We have performed a blind search for a gamma-ray transient of arbitrary duration and energy spectrum around the time of the LIGO gravitational-wave event GW150914 with the six-spacecraft interplanetary network (IPN). Four gamma-ray bursts were detected between 30 hr prior to the event and 6.1 hr after it, but none could convincingly be associated with GW150914. No other transients were detected down to limiting 15–150 keV fluences of roughly 5 ×10{sup −8}–5 × 10{sup −7} erg cm{sup −2}. We discuss the search strategies and temporal coverage of the IPN on the day of the event and compare the spatial coverage to the region where GW150914 originated. We also report the negative result of a targeted search for the Fermi -GBM event reported in conjunction with GW150914.

  5. Geoeffectiveness of interplanetary shocks controlled by impact angles: A review

    Science.gov (United States)

    Oliveira, D. M.; Samsonov, A. A.

    2018-01-01

    The high variability of the Sun's magnetic field is responsible for the generation of perturbations that propagate throughout the heliosphere. Such disturbances often drive interplanetary shocks in front of their leading regions. Strong shocks transfer momentum and energy into the solar wind ahead of them which in turn enhance the solar wind interaction with magnetic fields in its way. Shocks then eventually strike the Earth's magnetosphere and trigger a myriad of geomagnetic effects observed not only by spacecraft in space, but also by magnetometers on the ground. Recently, it has been revealed that shocks can show different geoeffectiveness depending closely on the angle of impact. Generally, frontal shocks are more geoeffective than inclined shocks, even if the former are comparatively weaker than the latter. This review is focused on results obtained from modeling and experimental efforts in the last 15 years. Some theoretical and observational background are also provided.

  6. The interplanetary magnetic field observed by Juno enroute to Jupiter

    Science.gov (United States)

    Gruesbeck, Jacob R.; Gershman, Daniel J.; Espley, Jared R.; Connerney, John E. P.

    2017-06-01

    The Juno spacecraft was launched on 5 August 2011 and spent nearly 5 years traveling through the inner heliosphere on its way to Jupiter. The Magnetic Field Investigation was powered on shortly after launch and obtained vector measurements of the interplanetary magnetic field (IMF) at sample rates from 1 to 64 samples/second. The evolution of the magnetic field with radial distance from the Sun is compared to similar observations obtained by Voyager 1 and 2 and the Ulysses spacecraft, allowing a comparison of the radial evolution between prior solar cycles and the current depressed one. During the current solar cycle, the strength of the IMF has decreased throughout the inner heliosphere. A comparison of the variance of the normal component of the magnetic field shows that near Earth the variability of the IMF is similar during all three solar cycles but may be less at greater radial distances.

  7. The Interplanetary Magnetic Field Observed by Juno Enroute to Jupiter

    Science.gov (United States)

    Gruesbeck, Jacob R.; Gershman, Daniel J.; Espley, Jared R.; Connerney, John E. P.

    2017-01-01

    The Juno spacecraft was launched on 5 August 2011 and spent nearly 5 years traveling through the inner heliosphere on its way to Jupiter. The Magnetic Field Investigation was powered on shortly after launch and obtained vector measurements of the interplanetary magnetic field (IMF) at sample rates from 1 to 64 samples/second. The evolution of the magnetic field with radial distance from the Sun is compared to similar observations obtained by Voyager 1 and 2 and the Ulysses spacecraft, allowing a comparison of the radial evolution between prior solar cycles and the current depressed one. During the current solar cycle, the strength of the IMF has decreased throughout the inner heliosphere. A comparison of the variance of the normal component of the magnetic field shows that near Earth the variability of the IMF is similar during all three solar cycles but may be less at greater radial distances.

  8. Transport of solar electrons in the turbulent interplanetary magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Ablaßmayer, J.; Tautz, R. C., E-mail: robert.c.tautz@gmail.com [Zentrum für Astronomie und Astrophysik, Technische Universität Berlin, Hardenbergstraße 36, D-10623 Berlin (Germany); Dresing, N., E-mail: dresing@physik.uni-kiel.de [Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, Leibnizstraße 11, D-24118 Kiel (Germany)

    2016-01-15

    The turbulent transport of solar energetic electrons in the interplanetary magnetic field is investigated by means of a test-particle Monte-Carlo simulation. The magnetic fields are modeled as a combination of the Parker field and a turbulent component. In combination with the direct calculation of diffusion coefficients via the mean-square displacements, this approach allows one to analyze the effect of the initial ballistic transport phase. In that sense, the model complements the main other approach in which a transport equation is solved. The major advancement is that, by recording the flux of particles arriving at virtual detectors, intensity and anisotropy-time profiles can be obtained. Observational indications for a longitudinal asymmetry can thus be explained by tracing the diffusive spread of the particle distribution. The approach may be of future help for the systematic interpretation of observations for instance by the solar terrestrial relations observatory (STEREO) and advanced composition explorer (ACE) spacecrafts.

  9. The acceleration of particles at propagating interplanetary shocks

    Science.gov (United States)

    Prinsloo, P. L.; Strauss, R. D. T.

    2017-12-01

    Enhancements of charged energetic particles are often observed at Earth following the eruption of coronal mass ejections (CMEs) on the Sun. These enhancements are thought to arise from the acceleration of those particles at interplanetary shocks forming ahead of CMEs, propagating into the heliosphere. In this study, we model the acceleration of these energetic particles by solving a set of stochastic differential equations formulated to describe their transport and including the effects of diffusive shock acceleration. The study focuses on how acceleration at halo-CME-driven shocks alter the energy spectra of non-thermal particles, while illustrating how this acceleration process depends on various shock and transport parameters. We finally attempt to establish the relative contributions of different seed populations of energetic particles in the inner heliosphere to observed intensities during selected acceleration events.

  10. Time delay of interplanetary magnetic field penetration into Earth's magnetotail

    Science.gov (United States)

    Rong, Z. J.; Lui, A. T. Y.; Wan, W. X.; Yang, Y. Y.; Shen, C.; Petrukovich, A. A.; Zhang, Y. C.; Zhang, T. L.; Wei, Y.

    2015-05-01

    Many previous studies have demonstrated that the interplanetary magnetic field (IMF) can control the magnetospheric dynamics. Immediate magnetospheric responses to the external IMF have been assumed for a long time. The specific processes by which IMF penetrates into magnetosphere, however, are actually unclear. Solving this issue will help to accurately interpret the time sequence of magnetospheric activities (e.g., substorm and tail plasmoids) exerted by IMF. With two carefully selected cases, we found that the penetration of IMF into magnetotail is actually delayed by 1-1.5 h, which significantly lags behind the magnetotail response to the solar wind dynamic pressure. The delayed time appears to vary with different auroral convection intensity, which may suggest that IMF penetration in the magnetotail is controlled considerably by the dayside reconnection. Several unfavorable cases demonstrate that the penetration lag time is more clearly identified when storm/substorm activities are not involved.

  11. The characteristic response of whistler mode waves to interplanetary shocks

    Science.gov (United States)

    Yue, C.; Chen, L.; Bortnik, J.; Ma, Q.; Thorne, R. M.; Angelopoulos, V.; Li, J.; An, X.; Zhou, C.

    2017-12-01

    Magnetospheric whistler mode waves play a key role in regulating the dynamics of the electron radiation belts. Recent satellite observations indicate a significant influence of interplanetary (IP) shocks on whistler mode wave power in the inner magnetosphere. In this study, we statistically investigate the response of whistler mode chorus and plasmaspheric hiss to IP shocks based on Van Allen Probes and THEMIS satellite observations. Immediately after the IP shock arrival, chorus wave power is usually intensified, often at dawn, while plasmaspheric hiss wave power predominantly decreases near the dayside but intensifies near the nightside. We conclude that chorus wave intensification outside the plasmasphere is probably associated with the suprathermal electron flux enhancement caused by the IP shock. On the other hand, the solar wind dynamic pressure increase changes the magnetic field configuration to favor ray penetration into the nightside and promote ray refraction away from the dayside, explaining the magnetic local time (MLT) dependent responses of plasmaspheric hiss waves following IP shock arrivals.

  12. The Interplanetary Internet: a communications infrastructure for Mars exploration

    Science.gov (United States)

    Burleigh, Scott; Cerf, Vinton; Durst, Robert; Fall, Kevin; Hooke, Adrian; Scott, Keith; Weiss, Howard

    2003-01-01

    A strategy is being developed whereby the current set of internationally standardized space data communications protocols can be incrementally evolved so that a first version of an operational "Interplanetary Internet" is feasible by the end of the decade. This paper describes its architectural concepts, discusses the current set of standard space data communications capabilities that exist to support Mars exploration and reviews proposed new developments. We also speculate that these current capabilities can grow to support future scenarios where human intelligence is widely distributed across the Solar System and day-to-day communications dialog between planets is routine. c2003 American Institute of Aeronautics and Astronautics. Published by Elsevier Science Ltd. All rights reserved.

  13. Doppler frequency in interplanetary radar and general relativity

    Science.gov (United States)

    Mcvittie, G. C.

    1972-01-01

    The change of frequency of an interplanetary radar signal sent from the earth to another planet or to a space probe is worked out according to general relativity. The Schwarzschild spacetime is employed and its null geodesics control the motion of the signals. Exact Doppler frequency formulas are derived for one-way and two-way radar in terms of an arbitrary Schwarzschild radial coordinate. A reduction to the special relativity case is used to interpret the formulas in terms of the relative radial velocity of emitter and target. The general relativity corrections are worked out approximately for each of three possible Schwarzschild radial coordinates, and a numerical example is given. The amount of the correction is different according as one or the other of the Schwarzschild coordinates is identified with the radius vector deduced from classical celestial mechanics. The identification problem is discussed.

  14. An Alternative Method for Identifying Interplanetary Magnetic Cloud Regions

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda-Gonzalez, A.; Prestes, A.; Klausner, V. [Laboratory of Physics and Astronomy, IP and D/Universidade do Vale do Paraíba—UNIVAP, São José dos Campos, SP (Brazil); Mendes, O. [Division of Space Geophysics, National Institute for Space Research, São José dos Campos, SP (Brazil); Calzadilla, A. [Department of Space Geophysics, Institute of Geophysics and Astronomy, Havana (Cuba); Domingues, M. O., E-mail: ojeda.gonzalez.a@gmail.com [Associate Laboratory of Applied Computing and Mathematics, National Institute for Space Research, São José dos Campos, SP (Brazil)

    2017-03-10

    Spatio-temporal entropy (STE) analysis is used as an alternative mathematical tool to identify possible magnetic cloud (MC) candidates. We analyze Interplanetary Magnetic Field (IMF) data using a time interval of only 10 days. We select a convenient data interval of 2500 records moving forward by 200 record steps until the end of the time series. For every data segment, the STE is calculated at each step. During an MC event, the STE reaches values close to zero. This extremely low value of STE is due to MC structure features. However, not all of the magnetic components in MCs have STE values close to zero at the same time. For this reason, we create a standardization index (the so-called Interplanetary Entropy, IE, index). This index is a worthwhile effort to develop new tools to help diagnose ICME structures. The IE was calculated using a time window of one year (1999), and it has a success rate of 70% over other identifiers of MCs. The unsuccessful cases (30%) are caused by small and weak MCs. The results show that the IE methodology identified 9 of 13 MCs, and emitted nine false alarm cases. In 1999, a total of 788 windows of 2500 values existed, meaning that the percentage of false alarms was 1.14%, which can be considered a good result. In addition, four time windows, each of 10 days, are studied, where the IE method was effective in finding MC candidates. As a novel result, two new MCs are identified in these time windows.

  15. Heliocentric distance dependence of the interplanetary magnetic field

    International Nuclear Information System (INIS)

    Behannon, K.W.

    1978-01-01

    Recent and ongoing planetary missions have provided and are continuing to provide extensive observations of the variations of the interplanetary magnetic field (IMF) both in time and with heliocentric distance from the sun. Large time variations in both the IMF and its fluctuations are observed. These are produced predominantly by dynamical processes in the interplanetary medium associated with stream interactions. Magnetic field variations near the sun are propagated to greater heliocentric distances, a process also contributing to the observed variability of the IMF. Temporal variations on a time scale comparable to or less than the corotation period complicate attempts to deduce radial gradients of the field and its fluctuations from the various observations. However, recent measurements inward to 0.46 AU and outward to 5 AU suggest that the radial component of the field on average decreases approximately as r -2 , as was predicted by Parker, while the azimuthal component decreases more rapidly than the r -1 dependence predicted by simple theory. Three sets of observations are consistent with r/sup -1.3/ dependence for vertical-barB/sub phi/vertical-bar. The temporal variability of solar wind speed is most likely the predominant contributor to this latter observational result. The long-term average azimuthal component radial gradient is probably consistent with the Parker r -1 dependence when solar wind speed variations are taken into account. The observations of the normal component magnitude vertical-barB/sub theta/vertical-bar are roughly consistent with a heliocentric distance dependence of r/sup -1.4/. The observed radial distance dependence of the total magnitude of the IMF is well described by the Parker formulation. There is observational evidence that amplitudes of fluctuations of the vector field with periods less than 1 day vary with heliocentric distance as approximately r/sup -3/2/, in agreement with theoretical models by Whang and Hollweg

  16. Autonomous aerobraking for low-cost interplanetary missions

    Science.gov (United States)

    Carrelli, David; O'Shaughnessy, Daniel; Strikwerda, Thomas; Kaidy, James; Prince, Jill; Powell, Richard

    2014-01-01

    Aerobraking has previously been used to reduce the propellant required to deliver an orbiter to its desired final orbit. In principle, aerobraking should be possible around any target planet or moon having sufficient atmosphere to permit atmospheric drag to provide a portion of the mission ΔV, in lieu of supplying all of the required ΔV propulsively. The spacecraft is flown through the upper atmosphere of the target using multiple passes, ensuring that the dynamic pressure and thermal loads remain within the spacecraft's design parameters. NASA has successfully conducted aerobraking operations four times, once at Venus and three times at Mars. While aerobraking reduces the fuel required, it does so at the expense of time (typically 3-6 months), continuous Deep Space Network (DSN) coverage, and a large ground staff. These factors can result in aerobraking being a very expensive operational phase of the mission. However, aerobraking has matured to the point that much of the daily operation could potentially be performed autonomously onboard the spacecraft, thereby reducing the required ground support and attendant aerobraking related costs. To facilitate a lower-risk transition from ground processing to an autonomous capability, the NASA Engineering and Safety Center (NESC) has assembled a team of experts in aerobraking and interplanetary guidance and control to develop a high-fidelity, flight-like simulation. This simulation will be used to demonstrate the overall feasibility while exploring the potential for staff and DSN coverage reductions that autonomous aerobraking might provide. This paper reviews the various elements of autonomous aerobraking and presents an overview of the various models and algorithms that must be transformed from the current ground processing methodology to a flight-like environment. Additionally the high-fidelity flight software test bed, being developed from models used in a recent interplanetary mission, will be summarized.

  17. 33 CFR 2.36 - Navigable waters of the United States, navigable waters, and territorial waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Navigable waters of the United States, navigable waters, and territorial waters. 2.36 Section 2.36 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY GENERAL JURISDICTION Jurisdictional Terms § 2.36 Navigable waters...

  18. Observations of interplanetary scintillation and their application to the space weather forecast

    International Nuclear Information System (INIS)

    Kojima, Masayoshi; Kakinuma, Takakiyo

    1989-01-01

    The interplanetary scintillation (IPS) method using natural radio sources can observe the solar wind near the sun and at high latitudes that have never been accessible to any spacecraft. Therefore, the IPS has been the most powerful method to observe the solar wind in three-dimensional space. Although the IPS method cannot predict when a flare will occur or when a filament will disappear, it can be used to forecast the propagation of interplanetary disturbances and to warn when they will attack the earth. Thus, the IPS method can be used to forecast recurrent interplanetary phenomena as well as transient phenomena. (author)

  19. Indoor navigation by image recognition

    Science.gov (United States)

    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.

  20. China Satellite Navigation Conference

    CERN Document Server

    Liu, Jingnan; Fan, Shiwei; Wang, Feixue

    2016-01-01

    These Proceedings present selected research papers from CSNC2016, held during 18th-20th May in Changsha, China. The theme of CSNC2016 is Smart Sensing, Smart Perception. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 12 topics to match the corresponding sessions in CSNC2016, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.

  1. Understanding satellite navigation

    CERN Document Server

    Acharya, Rajat

    2014-01-01

    This book explains the basic principles of satellite navigation technology with the bare minimum of mathematics and without complex equations. It helps you to conceptualize the underlying theory from first principles, building up your knowledge gradually using practical demonstrations and worked examples. A full range of MATLAB simulations is used to visualize concepts and solve problems, allowing you to see what happens to signals and systems with different configurations. Implementation and applications are discussed, along with some special topics such as Kalman Filter and Ionosphere. W

  2. Navigating Hypermasculine Terrains

    DEFF Research Database (Denmark)

    Henriksen, Ann-Karina Eske

    2017-01-01

    The study addresses how young women navigate urban terrains that are characterized by high levels of interpersonal aggression and crime. It is argued that young women apply a range of gendered tactics to establish safety and social mastery, and that these are framed by the limits and possibilities...... imposed by a street-based hypermasculine script. The analysis rests on an ethnographic study among 25 young Danish women aged 13 to 23 experienced in engaging in street-based physical violence. The study suggests that explorations of female tactics can provide a useful method of analysis for understanding...

  3. China Satellite Navigation Conference

    CERN Document Server

    Liu, Jingnan; Yang, Yuanxi; Fan, Shiwei; Yu, Wenxian

    2017-01-01

    These proceedings present selected research papers from CSNC2017, held during 23th-25th May in Shanghai, China. The theme of CSNC2017 is Positioning, Connecting All. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 12 topics to match the corresponding sessions in CSNC2017, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.

  4. Implementing a Near-Optimal Optical Receiver for Inter-Planetary Communication

    Data.gov (United States)

    National Aeronautics and Space Administration — Proposal Objective: Interplanetary communications signals are inherently weak at the receiver. In fact, for a desired data rate the received optical pulses may...

  5. GENESIS OF INTERPLANETARY INTERMITTENT TURBULENCE: A CASE STUDY OF ROPE–ROPE MAGNETIC RECONNECTION

    Energy Technology Data Exchange (ETDEWEB)

    Chian, Abraham C.-L.; Loew, Murray H. [Department of Biomedical Engineering, George Washington University, Washington, DC 20052 (United States); Feng, Heng Q. [Institute of Space Physics, Luoyang Normal University, Luoyang (China); Hu, Qiang [Department of Space Science and CSPAR, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Miranda, Rodrigo A. [UnB-Gama Campus, and Plasma Physics Laboratory, Institute of Physics, University of Brasília (UnB), Brasília DF 70910-900 (Brazil); Muñoz, Pablo R. [Department of Physics and Astronomy, University of La Serena, Av. Juan Cisternas 1200, La Serena (Chile); Sibeck, David G. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Wu, De J., E-mail: abraham.chian@gmail.com [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-12-01

    In a recent paper, the relation between current sheet, magnetic reconnection, and turbulence at the leading edge of an interplanetary coronal mass ejection was studied. We report here the observation of magnetic reconnection at the interface region of two interplanetary magnetic flux ropes. The front and rear boundary layers of three interplanetary magnetic flux ropes are identified, and the structures of magnetic flux ropes are reconstructed by the Grad–Shafranov method. A quantitative analysis of the reconnection condition and the degree of intermittency reveals that rope–rope magnetic reconnection is the most likely site for genesis of interplanetary intermittency turbulence in this event. The dynamic pressure pulse resulting from this reconnection triggers the onset of a geomagnetic storm.

  6. Spacecraft Position Estimation in Interplanetary Trajectories Using Star Trackers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Lynntech proposes a novel spacecraft position estimation method that leverages existing star trackers on board of a vehicle in an interplanetary trajectory for...

  7. Possible mechanism of the interplanetary medium effect on the diurnal rotation rate of the Earth

    International Nuclear Information System (INIS)

    Krymskij, P.F.

    1993-01-01

    Mechanism is proposed for effect of the solar wind and interplanetary magnetic field on the Earth rotation. In the mechanism base is Hall current generation in the plasma layer of the magnetosphere tail

  8. Ka Band Parabolic Deployable Antenna (KaPDA) for Interplanetary CubeSat Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ka Band Parabolic Deployable Antenna (KaPDA) for Interplanetary CubeSat Communications allowing moving up from UHF, S or X to get higher gain for a given diameter.

  9. Geomagnetic response of interplanetary coronal mass ejections in the Earth's magnetosphere

    Science.gov (United States)

    Badruddin; Mustajab, F.; Derouich, M.

    2018-05-01

    A coronal mass ejections (CME) is the huge mass of plasma with embedded magnetic field ejected abruptly from the Sun. These CMEs propagate into interplanetary space with different speed. Some of them hit the Earth's magnetosphere and create many types of disturbances; one of them is the disturbance in the geomagnetic field. Individual geomagnetic disturbances differ not only in their magnitudes, but the nature of disturbance is also different. It is, therefore, desirable to understand these differences not only to understand the physics of geomagnetic disturbances but also to understand the properties of solar/interplanetary structures producing these disturbances of different magnitude and nature. In this work, we use the spacecraft measurements of CMEs with distinct magnetic properties propagating in the interplanetary space and generating disturbances of different levels and nature. We utilize their distinct plasma and field properties to search for the interplanetary parameter(s) playing important role in influencing the geomagnetic response of different coronal mass ejections.

  10. On the solar origin of interplanetary disturbances observed in the vicinity of the Earth

    Directory of Open Access Journals (Sweden)

    N. Vilmer

    Full Text Available The solar origin of 40 interplanetary disturbances observed in the vicinity of the Earth between January 1997 and June 1998 is investigated in this paper. Analysis starts with the establishment of a list of Interplanetary Mass Ejections or ICMEs (magnetic clouds, flux ropes and ejecta and of Interplanetary Shocks measured at WIND for the period for which we had previously investigated the coupling of the interplanetary medium with the terrestrial ionospheric response. A search for associated coronal mass ejections (CMEs observed by LASCO/SOHO is then performed, starting from an estimation of the transit time of the inter-planetary perturbation from the Sun to the Earth, assumed to be achieved at a constant speed (i.e. the speed measured at 1 AU. EIT/SOHO and Nançay Radioheliograph (NRH observations are also used as proxies in this identification for the cases when LASCO observations do not allow one to firmly establish the association. The last part of the analysis concerns the identification of the solar source of the CMEs, performed using a large set of solar observations from X-ray to radio wavelengths. In the present study, this association is based on a careful examination of many data sets (EIT, NRH and H images and not on the use of catalogs and of Solar Geophysical Data reports. An association between inter-planetary disturbances and LASCO/CMEs or proxies on the disk is found for 36 interplanetary events. For 32 events, the solar source of activity can also be identified. A large proportion of cases is found to be associated with a flare signature in an active region, not excluding of course the involvement of a filament. Conclusions are finally drawn on the propagation of the disturbances in the interplanetary medium, the preferential association of disturbances detected close to the Earth’s orbit with halos or wide CMEs and the location on the solar disk of solar sources of the interplanetary disturbances during that period

  11. Multitarget Approaches to Robust Navigation

    Data.gov (United States)

    National Aeronautics and Space Administration — The performance, stability, and statistical consistency of a vehicle's navigation algorithm are vitally important to the success and safety of its mission....

  12. Advancements in Optical Navigation Capabilities

    Data.gov (United States)

    National Aeronautics and Space Administration — The Goddard Image Analysis and Navigation Tool (GIANT) is a tool that was developed for the Origins, Spectral Interpretation, Resource Identification,...

  13. Research in space science and technology. [including X-ray astronomy and interplanetary plasma physics

    Science.gov (United States)

    Beckley, L. E.

    1977-01-01

    Progress in various space flight research programs is reported. Emphasis is placed on X-ray astronomy and interplanetary plasma physics. Topics covered include: infrared astronomy, long base line interferometry, geological spectroscopy, space life science experiments, atmospheric physics, and space based materials and structures research. Analysis of galactic and extra-galactic X-ray data from the Small Astronomy Satellite (SAS-3) and HEAO-A and interplanetary plasma data for Mariner 10, Explorers 47 and 50, and Solrad is discussed.

  14. Propagation Characteristics of Two Coronal Mass Ejections from the Sun Far into Interplanetary Space

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaowei; Liu, Ying D.; Hu, Huidong; Wang, Rui, E-mail: liuxying@spaceweather.ac.cn [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-03-01

    Propagation of coronal mass ejections (CMEs) from the Sun far into interplanetary space is not well understood, due to limited observations. In this study we examine the propagation characteristics of two geo-effective CMEs, which occurred on 2005 May 6 and 13, respectively. Significant heliospheric consequences associated with the two CMEs are observed, including interplanetary CMEs (ICMEs) at the Earth and Ulysses , interplanetary shocks, a long-duration type II radio burst, and intense geomagnetic storms. We use coronagraph observations from SOHO /LASCO, frequency drift of the long-duration type II burst, in situ measurements at the Earth and Ulysses , and magnetohydrodynamic propagation of the observed solar wind disturbances at 1 au to track the CMEs from the Sun far into interplanetary space. We find that both of the CMEs underwent a major deceleration within 1 au and thereafter a gradual deceleration when they propagated from the Earth to deep interplanetary space, due to interactions with the ambient solar wind. The results also reveal that the two CMEs interacted with each other in the distant interplanetary space even though their launch times on the Sun were well separated. The intense geomagnetic storm for each case was caused by the southward magnetic fields ahead of the CME, stressing the critical role of the sheath region in geomagnetic storm generation, although for the first case there is a corotating interaction region involved.

  15. Shock parameter calculations at weak interplanetary shock waves

    Directory of Open Access Journals (Sweden)

    J. M. Gloag

    2005-02-01

    Full Text Available A large set of interplanetary shock waves observed using the Ulysses spacecraft is analysed in order to determine their local parameters. For the first time a detailed analysis is extended to the thermodynamic properties of a large number of events. The intention is to relate the shock parameters to the requirements set by MHD shock theory. A uniform approach is adopted in the selection of up and downstream regions for this analysis and applied to all the shock waves. Initially, the general case of a 3 component adiabatic plasma is considered. However, the calculation of magnetosonic and Alfvénic Mach numbers and the ratio of downstream to upstream entropy produce some unexpected results. In some cases there is no clear increase in entropy across the shock and also the magnetosonic Mach number can be less than 1. It is found that a more discerning use of data along with an empirical value for the polytropic index can raise the distribution of downstream to upstream entropy ratios to a more acceptable level. However, it is also realised that many of these shocks are at the very weakest end of the spectrum and associated phenomena may also contribute to the explanation of these results.

  16. Reference Design for a Simple, Durable and Refuelable Interplanetary Spacecraft

    Science.gov (United States)

    McConnell, B. S.; Tolley, A. M.

    This article describes a reference design for interplanetary vessels, composed mostly of water, that utilize simplified RF engines for low thrust, long duration propulsion, and hydrogen peroxide for short duration, high thrust burns. The electrothermal engines are designed to heat a wide range of liquid materials, possibly also milled solids or surface dusts. The system emphasizes simple components and processes based on older technologies, many well known since the 1960s, that are understandable, can process a variety of materials, and are easily serviced in flight. The goal is to radically simplify systems and their inter-dependencies, to a point where a reasonably skilled person can learn to operate these vessels, not unlike a sailboat, and to eliminate many design and testing bottlenecks in their construction. The use of water, or hydrogen peroxide generated in situ from that water, is multiply advantageous because it can be used for structure, consumption, irrigation, radiation and debris shielding, and thermal regulation, and thus greatly reduce dead weight by creating an almost fully consumable ship. This also enables the ship to utilize a wide range of in situ materials, and eventually obtain reaction mass from lower gravity sites. The ability to switch between low thrust, constant power and high thrust, short duration maneuvers will enable these ships to travel freely and reach many interesting destinations throughout the solar system. One can think of them as “spacecoaches”, not unlike the prairie schooners of the Old West, which were rugged, serviceable by tradesmen, and easily maintained.

  17. Multi-Objective Hybrid Optimal Control for Interplanetary Mission Planning

    Science.gov (United States)

    Englander, Jacob

    2015-01-01

    Preliminary design of low-thrust interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. Because low-thrust trajectory design is tightly coupled with systems design, power and propulsion characteristics must be chosen as well. In addition, a time-history of control variables must be chosen which defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated. The customer who commissions a trajectory design is not usually interested in a point solution, but rather the exploration of the trade space of trajectories between several different objective functions. This can be very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a multi-objective hybrid optimal control problem. The methods is demonstrated on hypothetical mission to the main asteroid belt and to Deimos.

  18. Analytical electron microscopy of a hydrated interplanetary dust particle

    International Nuclear Information System (INIS)

    Blake, D.F.; Bunch, T.E.; Mardinly, A.J.; Echer, C.J.

    1988-01-01

    A hydrated interplanetary dust particle (IDP), IDP number-sign Ames-Dec86-11, was selected for study from a number of IDPs collected by U-2 aircraft from Ames Research Center. The particle consists primarily of a relatively nonporous aggregate of fine-grained layer silicates, some of which are in situ hydrous alteration products of pre-existing grains. The particle shows no apparent alteration due to its deceleration upon atmospheric entry. The layer silicates have a bimodal size distribution, in which matrix phyllosilicates have an apparent grain size of 10-50 nm, and phyllosilicates that pseudomorphically replace pre-existing grains have a grain size of 1-10 nm. Despite this order of magnitude difference in crystallite size, both phases are smectites, according to quantitative analytical and electron diffraction data. Euhedral to subhedral pyrrhotites, which have grain size of 0.1-1.0 μm, have high nickel contents. Pre-existing grains that have been pseudomorphed by clays are commonly surrounded or decorated with fine-grained (10-20 nm) low-nickel pentlandite. Very fine grained (1-10 nm) magnetite occurs in clusters throughout the matrix. Several fragments of a Mg-Fe silicate phase, apparently a glass, are present

  19. Quasilinear simulations of interplanetary shocks and Earth's bow shock

    Science.gov (United States)

    Afanasiev, Alexandr; Battarbee, Markus; Ganse, Urs; Vainio, Rami; Palmroth, Minna; Pfau-Kempf, Yann; Hoilijoki, Sanni; von Alfthan, Sebastian

    2016-04-01

    We have developed a new self-consistent Monte Carlo simulation model for particle acceleration in shocks. The model includes a prescribed large-scale magnetic field and plasma density, temperature and velocity profiles and a self-consistently computed incompressible ULF foreshock under the quasilinear approximation. Unlike previous analytical treatments, our model is time dependent and takes full account of the anisotropic particle distributions and scattering in the wave-particle interaction process. We apply the model to the problem of particle acceleration at traveling interplanetary (IP) shocks and Earth's bow shock and compare the results with hybrid-Vlasov simulations and spacecraft observations. A qualitative agreement in terms of spectral shape of the magnetic fluctuations and the polarization of the unstable mode is found between the models and the observations. We will quantify the differences of the models and explore the region of validity of the quasilinear approach in terms of shock parameters. We will also compare the modeled IP shocks and the bow shock, identifying the similarities and differences in the spectrum of accelerated particles and waves in these scenarios. The work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 637324 (HESPERIA). The Academy of Finland is thanked for financial support. We acknowledge the computational resources provided by CSC - IT Centre for Science Ltd., Espoo.

  20. Impact of Interplanetary Magnetic Clouds On The Earthss Magnetosphere

    Science.gov (United States)

    Osherovich, V. A.; Benson, R. F.; Fainberg, J.

    We present data collected by Wind in March 2001 for magnetic clouds along with the Dst index and IMAGE/RPI sounder data in the magnetosphere. The normal state of the solar wind is characterized by a solar wind quasi-invariant (QI = (B2/8)/(v2/2) ) where B is the strength of the interplanetary magnetic field , v is the bulk solar wind speed and is the plasma density. While the yearly median QI follows sunspot num- bers with a 98 per cent correlation (Osherovich et al 1999), the arrival of a magnetic cloud increases QI by two orders of magnitude (Osherovich et al. 1997). Sounder stimulated resonances such as harmonics of the electron gyro frequency fce, electron plasma resonance fpe, Bernstein mode resonances Qn with frequencies above fpe and Dn resonances with frequencies below fpe are used to deduce the ratio between the electron gyro radius rce and the Debye radius rde. We suggest that the ratio rce/rde as a measure of the magnetospheric response to the magnetic cloud. We show that profiles of QI and rce/rde are similar and we find the delay time between the signal (QI) and the response (rce/rde). References: Osherovich, V.A., et al., Proc. 31st ESLAB Symp., ESTEC, Noordwijk, The Nether- lands, 171, 1997. Osherovich, V.A. , J. Fainberg and R.G. Stone, Geophys. Res. Lett., 26(16), 2597, 1999.

  1. Evidence linking coronal mass ejections with interplanetary magnetic clouds

    International Nuclear Information System (INIS)

    Wilson, R.M.; Hildner, E.

    1983-12-01

    Using proxy data for the occurrence of those mass ejections from the solar corona which are directed earthward, we investigate the association between the post-1970 interplanetary magnetic clouds of Klein and Burlaga and coronal mass ejections. The evidence linking magnetic clouds following shocks with coronal mass ejections is striking. Six of nine clouds observed at Earth were preceded an appropriate time earlier by meter-wave type II radio bursts indicative of coronal shock waves and coronal mass ejections occurring near central meridian. During the selected periods when no clouds were detected near Earth, the only type II bursts reported were associated with solar activity near the limbs. Where the proxy solar data to be sought are not so clearly suggested, that is, for clouds preceding interaction regions and clouds within cold magnetic enhancements, the evidence linking the clouds and coronal mass ejections is not as clear proxy data usually suggest many candidate mass-ejection events for each cloud. Overall, the data are consistent with and support the hypothesis suggested by Klein and Burlaga that magnetic clouds observed with spacecraft at 1 AU are manifestations of solar coronal mass ejection transients

  2. Coronal mass ejections and their sheath regions in interplanetary space

    Directory of Open Access Journals (Sweden)

    Emilia Kilpua

    2017-11-01

    Full Text Available Abstract Interplanetary coronal mass ejections (ICMEs are large-scale heliospheric transients that originate from the Sun. When an ICME is sufficiently faster than the preceding solar wind, a shock wave develops ahead of the ICME. The turbulent region between the shock and the ICME is called the sheath region. ICMEs and their sheaths and shocks are all interesting structures from the fundamental plasma physics viewpoint. They are also key drivers of space weather disturbances in the heliosphere and planetary environments. ICME-driven shock waves can accelerate charged particles to high energies. Sheaths and ICMEs drive practically all intense geospace storms at the Earth, and they can also affect dramatically the planetary radiation environments and atmospheres. This review focuses on the current understanding of observational signatures and properties of ICMEs and the associated sheath regions based on five decades of studies. In addition, we discuss modelling of ICMEs and many fundamental outstanding questions on their origin, evolution and effects, largely due to the limitations of single spacecraft observations of these macro-scale structures. We also present current understanding of space weather consequences of these large-scale solar wind structures, including effects at the other Solar System planets and exoplanets. We specially emphasize the different origin, properties and consequences of the sheaths and ICMEs.

  3. Toroidal Plasma Thruster for Interplanetary and Interstellar Space Flights

    International Nuclear Information System (INIS)

    Gorelenkov, N.N.; Zakharov, L.E.; Gorelenkova, M.V.

    2001-01-01

    This work involves a conceptual assessment for using the toroidal fusion reactor for deep space interplanetary and interstellar missions. Toroidal thermonuclear fusion reactors, such as tokamaks and stellarators, are unique for space propulsion, allowing for a design with the magnetic configuration localized inside toroidal magnetic field coils. Plasma energetic ions, including charged fusion products, can escape such a closed configuration at certain conditions, a result of the vertical drift in toroidal rippled magnetic field. Escaping particles can be used for direct propulsion (since toroidal drift is directed one way vertically) or to create and heat externally confined plasma, so that the latter can be used for propulsion. Deuterium-tritium fusion neutrons with an energy of 14.1 MeV also can be used for direct propulsion. A special design allows neutrons to escape the shield and the blanket of the tokamak. This provides a direct (partial) conversion of the fusion energy into the directed motion of the propellant. In contrast to other fusion concepts proposed for space propulsion, this concept utilizes the natural drift motion of charged particles out of the closed magnetic field configuration

  4. Solar flare nuclear gamma-rays and interplanetary proton events

    International Nuclear Information System (INIS)

    Cliver, E.W.; Forrest, D.J.; Cane, H.V.; Reames, D.V.; Mcguire, R.E.; Von Rosenvinge, T.T.

    1989-01-01

    Gamma-ray line (GRL) and solar energetic proton (SEP) events observed from February 1980 through January 1985 are compared in order to substantiate and better characterize the lack of correlation between GRL fluences and SEP event peak fluxes. The scatter plot of SEP event peak flux vs. GRL fluence is presented, and the ratio of 'solar' to 'interplanetary', about 10 MeV protons, is presented. It is shown that, while even large SEP events can originate in flares lacking detectable GRL emission, the converse case of flares with a significant GRL line fluence by lacking protons in space is rare. The ratio R of the number of about 10 MeV protons that produce GRL emission at the flare site to the number of about 10 MeV protons detected in space can vary from event to event by four orders of magnitude. There is a clear tendency for impulsive flares to have larger values of R than long-duration flares, where the flare time scale is given by the e-folding decay time of the associated soft X-ray emission. 103 refs

  5. The Characteristic Response of Whistler Mode Waves to Interplanetary Shocks

    Science.gov (United States)

    Yue, Chao; Chen, Lunjin; Bortnik, Jacob; Ma, Qianli; Thorne, Richard M.; Angelopoulos, Vassilis; Li, Jinxing; An, Xin; Zhou, Chen; Kletzing, Craig; Reeves, Geoffrey D.; Spence, Harlan E.

    2017-10-01

    Magnetospheric whistler mode waves play a key role in regulating the dynamics of the electron radiation belts. Recent satellite observations indicate a significant influence of interplanetary (IP) shocks on whistler mode wave power in the inner magnetosphere. In this study, we statistically investigate the response of whistler mode chorus and plasmaspheric hiss to IP shocks based on Van Allen Probes and THEMIS satellite observations. Immediately after the IP shock arrival, chorus wave power is usually intensified, often at postmidnight to prenoon sector, while plasmaspheric hiss wave power predominantly decreases near the dayside but intensifies near the nightside. We conclude that chorus wave intensification outside the plasmasphere is probably associated with the suprathermal electron flux enhancement caused by the IP shock. Through a simple ray tracing modeling assuming the scenario that plasmaspheric hiss is originated from chorus, we find that the solar wind dynamic pressure increase changes the magnetic field configuration to favor ray penetration in the nightside and promote ray refraction away from the dayside, potentially explaining the magnetic local time-dependent responses of plasmaspheric hiss waves following IP shock arrivals.

  6. The structure of plasma density irregularities in the interplanetary medium

    International Nuclear Information System (INIS)

    Singleton, D.G.

    1975-01-01

    Observations of the scintillation of sources 3C273 and 3C279 at 2292 MHz are described. The interpretation of the scintillation in terms of the structure of the plasma-density irregularities in the interplanetary medium is discussed. Scintillation index measurements obtained during these observations are combined with similar measurements at other frequencies reported in the literature. The resulting variation of the scintillation-index and observing-frequency product with source elongation is interpreted in terms of irregularities with a spatial spectrum of electron density which is of power law form. This result is reinforced by an analysis of the spectra of the observed scintillations. Several tests are applied to both the Fourier and Bessel spectra which illustrate conclusively that the irregularity spatial spectrum is of power law form, rather than the Gaussian form suggested by some workers. The spectra also show that the irregularities are isotopic within 0.2 AU of the sun, while there is some evidence that a degree of elongation normal to the direction of the motion of the irregularities may develop at slightly greater solar distances. The irregularity velocities determined are consistent with solar wind velocities. (author)

  7. Comprehension of Navigation Directions

    Science.gov (United States)

    Schneider, Vivian I.; Healy, Alice F.

    2000-01-01

    In an experiment simulating communication between air traffic controllers and pilots, subjects were given navigation instructions varying in length telling them to move in a space represented by grids on a computer screen. The subjects followed the instructions by clicking on the grids in the locations specified. Half of the subjects read the instructions, and half heard them. Half of the subjects in each modality condition repeated back the instructions before following them,and half did not. Performance was worse for the visual than for the auditory modality on the longer messages. Repetition of the instructions generally depressed performance, especially with the longer messages, which required more output than did the shorter messages, and especially with the visual modality, in which phonological recoding from the visual input to the spoken output was necessary. These results are explained in terms of the degrading effects of output interference on memory for instructions.

  8. Dynamic Transportation Navigation

    Science.gov (United States)

    Meng, Xiaofeng; Chen, Jidong

    Miniaturization of computing devices, and advances in wireless communication and sensor technology are some of the forces that are propagating computing from the stationary desktop to the mobile outdoors. Some important classes of new applications that will be enabled by this revolutionary development include intelligent traffic management, location-based services, tourist services, mobile electronic commerce, and digital battlefield. Some existing application classes that will benefit from the development include transportation and air traffic control, weather forecasting, emergency response, mobile resource management, and mobile workforce. Location management, i.e., the management of transient location information, is an enabling technology for all these applications. In this chapter, we present the applications of moving objects management and their functionalities, in particular, the application of dynamic traffic navigation, which is a challenge due to the highly variable traffic state and the requirement of fast, on-line computations.

  9. Signatures of interplanetary transients behind shocks and their associated near-surface solar activity

    Directory of Open Access Journals (Sweden)

    S. Bravo

    Full Text Available Interplanetary transients with particular signatures different from the normal solar wind have been observed behind interplanetary shocks and also without shocks. In this paper we have selected four well-known transient interplanetary signatures, namely: magnetic clouds, helium enhancements and bidirectional electron and ion fluxes, found in the solar wind behind shocks, and undertaken a correlative study between them and the corresponding solar observations. We found that although commonly different signatures appear in a single interplanetary transient event, they are not necessarily simultaneous, that is, they may belong to different plasma regions within the ejecta, which suggests that they may be generated by complex processes involving the ejection of plasma from different solar regions. We also found that more than 90% of these signatures correspond to cases when an Hα flare and/or the eruption of a filament occurred near solar central meridian between 1 and 4 days before the observation of the disturbance at 1 AU, the highest association being with flares taking place between 2 and 3 days before. The majority of the Hα flares were also accompanied by soft X-ray events. We also studied the longitudinal distribution of the associated solar events and found that between 80% and 90% of the interplanetary ejecta were associated with solar events within a longitudinal band of ±30° from the solar central meridian. An east-west asymmetry in the associated solar events seems to exist for some of the signatures. We also look for coronal holes adjacent to the site of the explosive event and find that they were present almost in every case.

    Key words. Interplanetary physics · Interplanetary shocks · Solar wind plasma · Solar physics · Flares and mass ejections

  10. Navigation System of Marks Areas - USACE IENC

    Data.gov (United States)

    Department of Homeland Security — These inland electronic Navigational charts (IENCs) were developed from available data used in maintenance of Navigation channels. Users of these IENCs should be...

  11. The use of database management systems and artificial intelligence in automating the planning of optical navigation pictures

    Science.gov (United States)

    Davis, Robert P.; Underwood, Ian M.

    1987-01-01

    The use of database management systems (DBMS) and AI to minimize human involvement in the planning of optical navigation pictures for interplanetary space probes is discussed, with application to the Galileo mission. Parameters characterizing the desirability of candidate pictures, and the program generating them, are described. How these parameters automatically build picture records in a database, and the definition of the database structure, are then discussed. The various rules, priorities, and constraints used in selecting pictures are also described. An example is provided of an expert system, written in Prolog, for automatically performing the selection process.

  12. Severe geomagnetic storms and Forbush decreases: interplanetary relationships reexamined

    Directory of Open Access Journals (Sweden)

    R. P. Kane

    2010-02-01

    Full Text Available Severe storms (Dst and Forbush decreases (FD during cycle 23 showed that maximum negative Dst magnitudes usually occurred almost simultaneously with the maximum negative values of the Bz component of interplanetary magnetic field B, but the maximum magnitudes of negative Dst and Bz were poorly correlated (+0.28. A parameter Bz(CP was calculated (cumulative partial Bz as sum of the hourly negative values of Bz from the time of start to the maximum negative value. The correlation of negative Dst maximum with Bz(CP was higher (+0.59 as compared to that of Dst with Bz alone (+0.28. When the product of Bz with the solar wind speed V (at the hour of negative Bz maximum was considered, the correlation of negative Dst maximum with VBz was +0.59 and with VBz(CP, 0.71. Thus, including V improved the correlations. However, ground-based Dst values have a considerable contribution from magnetopause currents (several tens of nT, even exceeding 100 nT in very severe storms. When their contribution is subtracted from Dst(nT, the residue Dst* representing true ring current effect is much better correlated with Bz and Bz(CP, but not with VBz or VBz(CP, indicating that these are unimportant parameters and the effect of V is seen only through the solar wind ram pressure causing magnetopause currents. Maximum negative Dst (or Dst* did not occur at the same hour as maximum FD. The time evolutions of Dst and FD were very different. The correlations were almost zero. Basically, negative Dst (or Dst* and FDs are uncorrelated, indicating altogether different mechanism.

  13. Acceleration of energetic protons by interplanetary shock waves

    International Nuclear Information System (INIS)

    Pesses, M.E.

    1979-01-01

    The acceleration of energetic protons in interplanetary magnetosonic fast-mode shock waves is studied via analytical modelling, numerical simulations and in situ observations. It is found that the only physical process by which energetic particles can gain energy from magnetosonic fast-mode shock waves is the one in which the particles cross the shock front several times during a shock encounter and the particle guiding centers gradient B and/or curvature drift at the shock front in the vector V x vector B electric field that exists in the shock rest frame. It is shown that it is physically impossible for charged particles to be Fermi accelerated by MHD shock waves or discontinuities. An analytical model is presented in which the particle-shock interaction is viewed in an intermediate frame in which the upstream and downstream vector V x vector B and partial derivative of vector B with respect to the electric fields are simultaneously zero. It is shown by numerical simulations that both reflected and transmitted particles conserve the first adiabatic invariant in the vector E = 0 frame for quasi-perpendicular shocks psi greater than or equal to 70 0 . The analytical predictions of post-shock energies and pitch angles and shock reflection and transmission coefficients are shown to be in excellent agreement with numerical simulation results. It is found that the 2 to 3 orders of magnitude increases in the Ca 1 MeV proton intensity frequently observed around the time of shock passage apparently cannot be produced by protons encountering the shocks just once, and that the average particle probably encounters the shocks several times prior to observation at Ca 1 MeV. The combination of vector V x vector B electric field mechanism and multiple shock encounters is shown to lead naturally to a differential energy spectrum that is an exponential in momentum

  14. The use of various interplanetary scintillation indices within geomagnetic forecasts

    Directory of Open Access Journals (Sweden)

    E. A. Lucek

    Full Text Available Interplanetary scintillation (IPS, the twinkling of small angular diameter radio sources, is caused by the interaction of the signal with small-scale plasma irregularities in the solar wind. The technique may be used to sense remotely the near-Earth heliosphere and observations of a sufficiently large number of sources may be used to track large-scale disturbances as they propagate from close to the Sun to the Earth. Therefore, such observations have potential for use within geomagnetic forecasts. We use daily data from the Mullard Radio Astronomy Observatory, made available through the World Data Centre, to test the success of geomagnetic forecasts based on IPS observations. The approach discussed here was based on the reduction of the information in a map to a single number or series of numbers. The advantages of an index of this nature are that it may be produced routinely and that it could ideally forecast both the occurrence and intensity of geomagnetic activity. We start from an index that has already been described in the literature, INDEX35. On the basis of visual examination of the data in a full skymap format modifications were made to the way in which the index was calculated. It was hoped that these would lead to an improvement in its forecasting ability. Here we assess the forecasting potential of the index using the value of the correlation coefficient between daily Ap and the IPS index, with IPS leading by 1 day. We also compare the forecast based on the IPS index with forecasts of Ap currently released by the Space Environment Services Center (SESC. Although we find that the maximum improvement achieved is small, and does not represent a significant advance in forecasting ability, the IPS forecasts at this phase of the solar cycle are of a similar quality to those made by SESC.

  15. Interstellar and Solar System Organic Matter Preserved in Interplanetary Dust

    Science.gov (United States)

    Messenger, Scott; Nakamura-Messenger, Keiko

    2015-01-01

    Interplanetary dust particles (IDPs) collected in the Earth's stratosphere derive from collisions among asteroids and by the disruption and outgassing of short-period comets. Chondritic porous (CP) IDPs are among the most primitive Solar System materials. CP-IDPs have been linked to cometary parent bodies by their mineralogy, textures, C-content, and dynamical histories. CP-IDPs are fragile, fine-grained (less than um) assemblages of anhydrous amorphous and crystalline silicates, oxides and sulfides bound together by abundant carbonaceous material. Ancient silicate, oxide, and SiC stardust grains exhibiting highly anomalous isotopic compositions are abundant in CP-IDPs, constituting 0.01 - 1 % of the mass of the particles. The organic matter in CP-IDPs is isotopically anomalous, with enrichments in D/H reaching 50x the terrestrial SMOW value and 15N/14N ratios up to 3x terrestrial standard compositions. These anomalies are indicative of low T (10-100 K) mass fractionation in cold molecular cloud or the outermost reaches of the protosolar disk. The organic matter shows distinct morphologies, including sub-um globules, bubbly textures, featureless, and with mineral inclusions. Infrared spectroscopy and mass spectrometry studies of organic matter in IDPs reveals diverse species including aliphatic and aromatic compounds. The organic matter with the highest isotopic anomalies appears to be richer in aliphatic compounds. These materials also bear similarities and differences with primitive, isotopically anomalous organic matter in carbonaceous chondrite meteorites. The diversity of the organic chemistry, morphology, and isotopic properties in IDPs and meteorites reflects variable preservation of interstellar/primordial components and Solar System processing. One unifying feature is the presence of sub-um isotopically anomalous organic globules among all primitive materials, including IDPs, meteorites, and comet Wild-2 samples returned by the Stardust mission.

  16. Automated trajectory planning for multiple-flyby interplanetary missions

    Science.gov (United States)

    Englander, Jacob

    Many space mission planning problems may be formulated as hybrid optimal control problems (HOCP), i.e. problems that include both real-valued variables and categorical variables. In interplanetary trajectory design problems the categorical variables will typically specify the sequence of planets at which to perform flybys, and the real-valued variables will represent the launch date, ight times between planets, magnitudes and directions of thrust, flyby altitudes, etc. The contribution of this work is a framework for the autonomous optimization of multiple-flyby interplanetary trajectories. The trajectory design problem is converted into a HOCP with two nested loops: an "outer-loop" that finds the sequence of flybys and an "inner-loop" that optimizes the trajectory for each candidate yby sequence. The problem of choosing a sequence of flybys is posed as an integer programming problem and solved using a genetic algorithm (GA). This is an especially difficult problem to solve because GAs normally operate on a fixed-length set of decision variables. Since in interplanetary trajectory design the number of flyby maneuvers is not known a priori, it was necessary to devise a method of parameterizing the problem such that the GA can evolve a variable-length sequence of flybys. A novel "null gene" transcription was developed to meet this need. Then, for each candidate sequence of flybys, a trajectory must be found that visits each of the flyby targets and arrives at the final destination while optimizing some cost metric, such as minimizing ▵v or maximizing the final mass of the spacecraft. Three different classes of trajectory are described in this work, each of which requireda different physical model and optimization method. The choice of a trajectory model and optimization method is especially challenging because of the nature of the hybrid optimal control problem. Because the trajectory optimization problem is generated in real time by the outer-loop, the inner

  17. 33 CFR 66.05-100 - Designation of navigable waters as State waters for private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Designation of navigable waters as State waters for private aids to navigation. 66.05-100 Section 66.05-100 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State...

  18. NOAA Electronic Navigational Charts (ENC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Office of Coast Survey (OCS) has been involved in the development of a NOAA Electronic Navigational Chart (NOAA ENC) suite to support the marine transportation...

  19. Comparison of comet 81P/Wild 2 dust with interplanetary dust from comets.

    Science.gov (United States)

    Ishii, Hope A; Bradley, John P; Dai, Zu Rong; Chi, Miaofang; Kearsley, Anton T; Burchell, Mark J; Browning, Nigel D; Molster, Frank

    2008-01-25

    The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials.

  20. Interplanetary Shocks and the Resulting Geomagnetically Induced Currents at the Equator

    Science.gov (United States)

    Carter, B. A.; Yizengaw, E.; Pradipta, R.; Halford, A. J.; Norman, R.; Zhang, K.

    2015-12-01

    Geomagnetically induced currents (GICs) caused by interplanetary shocks represent a serious space weather threat to modern technological infrastructure. The arrival of interplanetary shocks drives magnetosphere and ionosphere currents systems, which then induce electric currents at ground level. The impact of these currents at high latitudes has been extensively researched, but the magnetic equator has been largely overlooked. In this paper, we investigate the potential effects of interplanetary shocks on the equatorial region and demonstrate that their magnetic signature is amplied by the equatorial electrojet. This local amplication substantially increases the region's susceptibility to GICs. Importantly, this result applies to both geomagnetic storms and quiet periods, and thus represents a paradigm shift in our understanding of adverse space weather impacts on technological infrastructure.

  1. Relationship between the amplitude of geomagnetic Pc 3 pulsations and parameters of the interplanetary medium

    International Nuclear Information System (INIS)

    Kuklin, G.V.; Parkhomov, V.A.; Vinogradov, P.A.

    1983-01-01

    The dependence of Pc 3 amplitudes (T=10-45 s) on solar wind velocity, particle density, components of the interplanetary magnetic field (IMF) and on the Mach-Alfven number (Msub(A)) are discussed. By means of a statistical multivariate analysis of experimental data it has been shown that the pulsation amplitude is most closely connected with the solar wind velocity. A significant but less close correlation was found between Pc 3 amplitudes and the components of the interplanetary magnetic field vector in the ecliptic plane. The nature of the relationship of Pc 3 with solar wind and IMF parameters are discussed. (author)

  2. Compact autonomous navigation system (CANS)

    Science.gov (United States)

    Hao, Y. C.; Ying, L.; Xiong, K.; Cheng, H. Y.; Qiao, G. D.

    2017-11-01

    Autonomous navigation of Satellite and constellation has series of benefits, such as to reduce operation cost and ground station workload, to avoid the event of crises of war and natural disaster, to increase spacecraft autonomy, and so on. Autonomous navigation satellite is independent of ground station support. Many systems are developed for autonomous navigation of satellite in the past 20 years. Along them American MANS (Microcosm Autonomous Navigation System) [1] of Microcosm Inc. and ERADS [2] [3] (Earth Reference Attitude Determination System) of Honeywell Inc. are well known. The systems anticipate a series of good features of autonomous navigation and aim low cost, integrated structure, low power consumption and compact layout. The ERADS is an integrated small 3-axis attitude sensor system with low cost and small volume. It has the Earth center measurement accuracy higher than the common IR sensor because the detected ultraviolet radiation zone of the atmosphere has a brightness gradient larger than that of the IR zone. But the ERADS is still a complex system because it has to eliminate many problems such as making of the sapphire sphere lens, birefringence effect of sapphire, high precision image transfer optical fiber flattener, ultraviolet intensifier noise, and so on. The marginal sphere FOV of the sphere lens of the ERADS is used to star imaging that may be bring some disadvantages., i.e. , the image energy and attitude measurements accuracy may be reduced due to the tilt image acceptance end of the fiber flattener in the FOV. Besides Japan, Germany and Russia developed visible earth sensor for GEO [4] [5]. Do we have a way to develop a cheaper/easier and more accurate autonomous navigation system that can be used to all LEO spacecraft, especially, to LEO small and micro satellites? To return this problem we provide a new type of the system—CANS (Compact Autonomous Navigation System) [6].

  3. Link between interplanetary & cometary dust: Polarimetric observations and space studies with Rosetta & Eye-Sat

    Science.gov (United States)

    Levasseur-Regourd, Anny-Chantal; Gaboriaud, Alain; Buil, Christian; Ressouche, Antoine; Lasue, J.; Palun, Adrien; Apper, Fabien; Elmaleh, Marc

    Intensity and linear polarization observations of the solar light scattered by interplanetary dust, the so-called zodiacal light, provide information on properties of the dust particles, such as their spatial density, local changes, morphology and albedo. Earth-based polarimetric observations, with a resolution of 5° or more, have been used to derive the polarization phase curve of interplanetary dust particles and to establish that the polarization at 90° phase angle increases with increasing solar distance, at least up to 1.5 au in the ecliptic, while the albedo decreases [1, 2]. Analysis of such studies will be revisited. Numerical simulations of the polarimetric behavior of interplanetary dust particles strongly suggest that, in the inner solar system, interplanetary dust particles consist of absorbing (e.g., organic compounds) and less absorbing (e.g., silicates) materials, that radial changes originate in a decrease of organics with decreasing solar distance (probably due to alteration processes), and that a significant fraction of the interplanetary dust is of cometary origin, in agreement with dynamical studies [3, 4]. The polarimetric behaviors of interplanetary dust and cometary dust particles seem to present striking similarities. The properties of cometary dust particles, as derived from remote polarimetric observations of comets including 67P/Churyumov-Gerasimenko, the target of the Rosetta rendezvous mission, at various wavelengths, will be summarized [5, 6]. The ground truth expected from Rosetta dust experiments, i.e., MIDAS, COSIMA, GIADA, about dust particles’ morphology, composition, and evolution (with distance to the nucleus before Philae release and with distance to the Sun before and after perihelion passage) over the year and a half of nominal mission, will be discussed. Finally, the Eye-Sat nanosatellite will be presented. This triple cubesat, developed by students from engineering schools working as interns at CNES, is to be launched

  4. 33 CFR 401.54 - Interference with navigation aids.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Interference with navigation aids. 401.54 Section 401.54 Navigation and Navigable Waters SAINT LAWRENCE SEAWAY DEVELOPMENT CORPORATION... with navigation aids. (a) Aids to navigation shall not be interfered with or used as moorings. (b) No...

  5. Nonlinear generation of the fundamental radiation of interplanetary type III radio bursts

    International Nuclear Information System (INIS)

    Chian, A.C.L.; Alves, M.V.

    1988-01-01

    A new generation mechanism of interplanetary type III radio bursts at the fundamental electron plasma frequency is discussed. It is shown that the electromagnetic oscillating two-stream instability, driven by two oppositely propagating Langmuir waves, can account for the experimental observations. In particular, the major difficulties encountered by the previously considered electromagnetic decay instability are removed. 19 references

  6. Relation of geomagnetic activity index variations with parameters of interplanetary scintillations

    International Nuclear Information System (INIS)

    Vlasov, V.I.; Shishov, V.I.; Shishova, T.D.

    1985-01-01

    A correlation between the Asub(p)-index of geomagnetic activity, index of interplanetary scintillations and solar wind velocity, has been considered depending on the spatial position of the interplanetary plasma (IPP) regions under study. It is shown, that the scintillation index can be used to forecast the geomagnetic activity, whereas the solar wind velocity can not be used for the purpose. Heliolongitudinal dependence of geoeffectiveness of IPP sreading perturbations agrees well with their structure in the heliolongitudinal cross section (and, on the whole, with the angular structure and direction of IPP perturbation spread). To use interplanetary scintillations in forecasting the geomagnetic activity (on the level of correlation not below 0.5), the angular distance of the investigated IPP regions relative to the Sun-Earth line on the average should not exceed 30-40 deg. The time of delay between the moments of observation of variations in the scintillation index the time of passage of the corresponding heliocentric distances at an average rate of the interplanetary perturbation spread approximately 500 km/s

  7. Integrated Vehicle and Trajectory Design of Small Spacecraft with Electric Propulsion for Earth and Interplanetary Missions

    Science.gov (United States)

    Spangelo, Sara; Dalle, Derek; Longmier, Benjamin

    2015-01-01

    This paper investigates the feasibility of Earth-transfer and interplanetary mission architectures for miniaturized spacecraft using emerging small solar electric propulsion technologies. Emerging small SEP thrusters offer significant advantages relative to existing technologies and will enable U-class systems to perform trajectory maneuvers with significant Delta V requirements. The approach in this paper is unique because it integrates trajectory design with vehicle sizing and accounts for the system and operational constraints of small U-class missions. The modeling framework includes integrated propulsion, orbit, energy, and external environment dynamics and systems-level power, energy, mass, and volume constraints. The trajectory simulation environment models orbit boosts in Earth orbit and flyby and capture trajectories to interplanetary destinations. A family of small spacecraft mission architectures are studied, including altitude and inclination transfers in Earth orbit and trajectories that escape Earth orbit and travel to interplanetary destinations such as Mercury, Venus, and Mars. Results are presented visually to show the trade-offs between competing performance objectives such as maximizing available mass and volume for payloads and minimizing transfer time. The results demonstrate the feasibility of using small spacecraft to perform significant Earth and interplanetary orbit transfers in less than one year with reasonable U-class mass, power, volume, and mission durations.

  8. Interplanetary Space Weather Effects on Lunar Reconnaissance Orbiter Avalanche Photodiode Performance

    Science.gov (United States)

    Clements, E. B.; Carlton, A. K.; Joyce, C. J.; Schwadron, N. A.; Spence, H. E.; Sun, X.; Cahoy, K.

    2016-01-01

    Space weather is a major concern for radiation-sensitive space systems, particularly for interplanetary missions, which operate outside of the protection of Earth's magnetic field. We examine and quantify the effects of space weather on silicon avalanche photodiodes (SiAPDs), which are used for interplanetary laser altimeters and communications systems and can be sensitive to even low levels of radiation (less than 50 cGy). While ground-based radiation testing has been performed on avalanche photodiode (APDs) for space missions, in-space measurements of SiAPD response to interplanetary space weather have not been previously reported. We compare noise data from the Lunar Reconnaissance Orbiter (LRO) Lunar Orbiter Laser Altimeter (LOLA) SiAPDs with radiation measurements from the onboard Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument. We did not find any evidence to support radiation as the cause of changes in detector threshold voltage during radiation storms, both for transient detector noise and long-term average detector noise, suggesting that the approximately 1.3 cm thick shielding (a combination of titanium and beryllium) of the LOLA detectors is sufficient for SiAPDs on interplanetary missions with radiation environments similar to what the LRO experienced (559 cGy of radiation over 4 years).

  9. The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

    DEFF Research Database (Denmark)

    Vršnak, B.; Žic, T.; Falkenberg, Thea Vilstrup

    2010-01-01

    Context. The propagation of interplanetary coronal mass ejections (ICMEs) and the forecast of their arrival on Earth is one of the central issues of space weather studies. Aims. We investigate to which degree various ICME parameters (mass, size, take-off speed) and the ambient solar-wind parameters...

  10. Non-radial solar wind flows induced by the motion of interplanetary coronal mass ejections

    Directory of Open Access Journals (Sweden)

    M. Owens

    2004-12-01

    Full Text Available A survey of the non-radial flows (NRFs during nearly five years of interplanetary observations revealed the average non-radial speed of the solar wind flows to be ~30km/s, with approximately one-half of the large (>100km/s NRFs associated with ICMEs. Conversely, the average non-radial flow speed upstream of all ICMEs is ~100km/s, with just over one-third preceded by large NRFs. These upstream flow deflections are analysed in the context of the large-scale structure of the driving ICME. We chose 5 magnetic clouds with relatively uncomplicated upstream flow deflections. Using variance analysis it was possible to infer the local axis orientation, and to qualitatively estimate the point of interception of the spacecraft with the ICME. For all 5 events the observed upstream flows were in agreement with the point of interception predicted by variance analysis. Thus we conclude that the upstream flow deflections in these events are in accord with the current concept of the large-scale structure of an ICME: a curved axial loop connected to the Sun, bounded by a curved (though not necessarily circular cross section.

    Key words. Interplanetary physics (flare and stream dynamics; interplanetary magnetic fields; interplanetary shocks

  11. Mie scattering of the interplanetary magnetic field by the whole moon

    Science.gov (United States)

    Sonett, C. P.; Colburn, D. S.

    1974-01-01

    Based on the results of the Apollo magnetometer experiments, it is shown that the wavelength spectrum of the fluctuations of the interplanetary magnetic field includes scales consistent with the radius of the moon. Quadrupole and possibly octupole magnetic multipoles are found in the data and indicate that the moon is excited in several modes.

  12. Impact of interplanetary shock on parameters of plasma turbulence in the Earth's magnetosheath

    Science.gov (United States)

    Rakhmanova, L. S.; Riazantseva, M. O.; Borodkova, N. L.; Sapunova, O. V.; Zastenker, G. N.

    2017-11-01

    Data from the BMSW spectrometer, which measures the ion flux value and sometimes plasma parameters with a time resolution of 31 ms, allow the study of the parameters of turbulence of the solar wind and magnetosheath plasma on kinetic scales. In this work, the frequency spectra of the ion flux fluctuations before and after recording the interplanetary shock front in the Earth's magnetosheath are compared based on these data. It is shown that, in contrast to the solar wind, where the exponential decay of the spectrum often occurs after the shock front on the kinetic scales, no such phenomenon is observed in the magnetosheath: the spectrum on these scales can be approximated by a power function in all the cases considered. In half of these cases, the spectrum slope on the kinetic scales does not change during the interplanetary shock propagation. The results indicate a weak impact of interplanetary shock waves on the parameters of the plasma turbulence. In addition, it is shown that an interplanetary shock does not change the level of intermittency of the ion flux in the magnetosheath at both low and high level before the front.

  13. DECLINE AND RECOVERY OF THE INTERPLANETARY MAGNETIC FIELD DURING THE PROTRACTED SOLAR MINIMUM

    International Nuclear Information System (INIS)

    Smith, Charles W.; Schwadron, Nathan A.; DeForest, Craig E.

    2013-01-01

    The interplanetary magnetic field (IMF) is determined by the amount of solar magnetic flux that passes through the top of the solar corona into the heliosphere, and by the dynamical evolution of that flux. Recently, it has been argued that the total flux of the IMF evolves over the solar cycle due to a combination of flux that extends well outside of 1 AU and is associated with the solar wind, and additionally, transient flux associated with coronal mass ejections (CMEs). In addition to the CME eruption rate, there are three fundamental processes involving conversion of magnetic flux (from transient to wind-associated), disconnection, and interchange reconnection that control the levels of each form of magnetic flux in the interplanetary medium. This is distinct from some earlier models in which the wind-associated component remains steady across the solar cycle. We apply the model of Schwadron et al. that quantifies the sources, interchange, and losses of magnetic flux to 50 yr of interplanetary data as represented by the Omni2 data set using the sunspot number as a proxy for the CME eruption rate. We do justify the use of that proxy substitution. We find very good agreement between the predicted and observed interplanetary magnetic flux. In the absence of sufficient CME eruptions, the IMF falls on the timescale of ∼6 yr. A key result is that rising toroidal flux resulting from CME eruption predates the increase in wind-associated IMF

  14. The smallest source region of an interplanetary magnetic cloud: A mini-sigmoid

    Science.gov (United States)

    Mandrini, C. H.; Pohjolainen, S.; Dasso, S.; Green, L. M.; Démoulin, P.; van Driel-Gesztelyi, L.; Foley, C.; Copperwheat, C.

    We provide evidence for the smallest sigmoid eruption - CME - interplanetary magnetic cloud event ever observed by combining multi-wavelength remote sensing and in situ observations, as well as computing the coronal and interplanetary magnetic fields. The tiny bipole had 100 times less flux than an average active region (AR). It had a sigmoidal structure in the corona and we detected a very high level of twist in its magnetic field. On 11 May 1998, at about 8 UT, the sigmoid underwent eruption evidenced by expanding elongated EUV loops, dimmings and formation of a cusp. The Wind spacecraft, 4.5 days later, detected one of the smallest magnetic clouds (MC) ever identified (100 times less magnetic flux than an average MC). The link between the EUV bright point eruption and the interplanetary MC is supported by several pieces of evidence: timing, same coronal loop and MC orientation relative to the ecliptic, same magnetic field direction and magnetic helicity sign in the coronal loops and in the MC, comparable magnetic flux measured in the dimming regions and in the interplanetary MC and, most importantly, the pre- to post-event change of magnetic helicity in the solar corona is found to be comparable to the helicity content of the cloud.

  15. High-latitude ionospheric convection during strong interplanetary magnetic field B-y

    DEFF Research Database (Denmark)

    Huang, C.S.; Sofko, G.J.; Murr, D.

    1999-01-01

    . The interplanetary magnetic field (IMF) conditions corresponding to the occurrence of the ionospheric convection were B-x approximate to 1 nT, B-y approximate to 10 nT, and B-z y). We have compared our observations with statistical patterns and MHD numerical models for similar IMF...

  16. Effect of Interplanetary Magnetic Field and Disturb Storm Time on H ...

    Indian Academy of Sciences (India)

    E). We also study the effect of vertical component of interplanetary magnetic field (IMF) on the variation of the magnitude of H component during storm time of April, July and. November 2004. Results show that before sudden storm commencement. (SSC) time magnitude of H component and IMF show smooth variation but.

  17. Effect of Interplanetary Magnetic Field and Disturb Storm Time on H ...

    Indian Academy of Sciences (India)

    There are three panels (I–II–III) in Fig. 1. First panel shows the Dst of successive magnetic storm while second and third panels show the variation in H component deviation and Interplanetary Magnetic Field respectively. Graphs show the results of three magnetic storms dated 9 April, 10 April and 12 April, 2004. The upper.

  18. The measurement of interplanetary scintillations in conditions of strong radio interference

    International Nuclear Information System (INIS)

    Duffett-Smith, P.J.

    1980-01-01

    Observations of interplanetary scintillations (IPS) are often severely limited by interference from man-made transmissions within the receiver pass-band. A new method of measuring IPS is described which can give useful data even in conditions of bad interference. (author)

  19. Hysteresis loops of Cosmic Ray intensity decreases versus solar and interplanetary parameters

    Directory of Open Access Journals (Sweden)

    R. P. Kane

    2007-10-01

    Full Text Available The purpose of this study was to examine the correlation between CR (Cosmic Ray intensity and solar, interplanetary and terrestrial parameters. The hysteresis loops of (CR versus those of several solar parameters showed narrow loops in even cycles 20, 22 and broad loops in odd cycles 19, 21, as also in the recent odd cycle 23. Hysteresis plots for CR versus interplanetary number density N and speed V were erratic and uncertain (broad and narrow, all mixed up. Plots of CR versus Interplanetary magnetic field (IMF B seemed to be narrow for even as well as odd cycles. Hysteresis loops between CR and other interplanetary parameters were not clear-cut. The same was true for terrestrial parameters. During sunspot maximum years 2000–2003 of cycle 23, there is a double peak structure in all parameters. Whereas CR have a peak spacing of ~30 months, sunspots and Tilt angle have a spacing of only ~20 months. The solar open magnetic flux and the Voyager 1 magnetic field have a spacing of ~25 months. The solar polar magnetic field reverses later than the first peak of all parameters and hence, could not be a direct cause (as if effect started before the cause and lasted for several months more after the cause disappeared. It seems that CR modulation is mainly guided by magnetic configurations deep in the heliosphere, which may not have a simple relationship with parameters near Earth or near Sun.

  20. Long-term Regularities in Distribution of Global Solar and Interplanetary Magnetic Fields

    Czech Academy of Sciences Publication Activity Database

    Ambrož, Pavel

    2013-01-01

    Roč. 37, č. 2 (2013), s. 637-642 ISSN 1845-8319. [Hvar Astrophysical Colloquium /12./. Hvar, 03.09.2012-07.09.2012] R&D Projects: GA AV ČR IAA300030808 Institutional support: RVO:67985815 Keywords : interplanetary magnetic field * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  1. GPS Navigation and Tracking Device

    Directory of Open Access Journals (Sweden)

    Yahya Salameh Khraisat

    2011-10-01

    Full Text Available Since the introduction of GPS Navigation systems in the marketplace, consumers and businesses have been coming up with innovative ways to use the technology in their everyday life. GPS Navigation and Tracking systems keep us from getting lost when we are in strange locations, they monitor children when they are away from home, keep track of business vehicles and can even let us know where a philandering partner is at all times. Because of this we attend to build a GPS tracking device to solve the mentioned problems. Our work consists of the GPS module that collects data from satellites and calculates the position information before transmitting them to the user’s PC (of Navigation system or observers (of Tracking System using wireless technology (GSM.

  2. Behavioral Mapless Navigation Using Rings

    Science.gov (United States)

    Monroe, Randall P.; Miller, Samuel A.; Bradley, Arthur T.

    2012-01-01

    This paper presents work on the development and implementation of a novel approach to robotic navigation. In this system, map-building and localization for obstacle avoidance are discarded in favor of moment-by-moment behavioral processing of the sonar sensor data. To accomplish this, we developed a network of behaviors that communicate through the passing of rings, data structures that are similar in form to the sonar data itself and express the decisions of each behavior. Through the use of these rings, behaviors can moderate each other, conflicting impulses can be mediated, and designers can easily connect modules to create complex emergent navigational techniques. We discuss the development of a number of these modules and their successful use as a navigation system in the Trinity omnidirectional robot.

  3. GPS Navigation and Tracking Device

    OpenAIRE

    Yahya Salameh Khraisat; Mohammad Al-Khateeb; Yahya Abu-Alreesh; Anas Ayyash; Osama Lahlouh

    2011-01-01

    Since the introduction of GPS Navigation systems in the marketplace, consumers and businesses have been coming up with innovative ways to use the technology in their everyday life. GPS Navigation and Tracking systems keep us from getting lost when we are in strange locations, they monitor children when they are away from home, keep track of business vehicles and can even let us know where a philandering partner is at all times. Because of this we attend to build a GPS tracking device to solve...

  4. Surface navigation on Mars with a Navigation Satellite

    Science.gov (United States)

    Vijayaraghavan, A.; Thurman, Sam W.; Kahn, Robert D.; Hastrup, Rolf C.

    Radiometric navigation data from the Deep Space Network (DSN) stations on the earth to transponders and other surface elements such as rovers and landers on Mars, can determine their positions to only within a kilometer in inertial space. The positional error is mostly in the z-component of the surface element parallel to the Martian spin-axis. However, with Doppler and differenced-Doppler data from a Navigation Satellite in orbit around Mars to two or more of such transponders on the planetary surface, their positions can be determined to within 15 meters (or 20 meters for one-way Doppler beacons on Mars) in inertial space. In this case, the transponders (or other vehicles) on Mars need not even be capable of directly communicating to the earth. When the Navigation Satellite data is complemented by radiometric observations from the DSN stations also, directly to the surface elements on Mars, their positions can be determined to within 3 meters in inertial space. The relative positions of such surface elements on Mars (relative to one another) in Mars-fixed coordinates, however, can be determined to within 5 meters from simply range and Doppler data from the DSN stations to the surface elements. These results are obtained from covariance studies assuming X-band data noise levels and data-arcs not exceeding 10 days. They are significant in the planning and deployment of a Mars-based navigation network necessary to support real-time operations during critical phases of manned exploration of Mars.

  5. The interaction of a very large interplanetary magnetic cloud with the magnetosphere and with cosmic rays

    International Nuclear Information System (INIS)

    Lepping, R.P.; Burlaga, L.F.; Ogilvie, K.W.; Tsurutani, B.T.; Lazarus, A.J.; Evans, D.S.; Klein, L.W.

    1991-01-01

    A large interplanetary magnetic cloud has been observed in the mid-December 1982 data from ISEE 3. It is estimated to have a heliocentric radial extent of approx-gt 0.4 AU, making it one of the largest magnetic clouds yet observed at 1 AU. The magnetic field measured throughout the main portion of the cloud was fairly tightly confined to a plane as it changed direction by 174 degree while varying only moderately in magnitude. Throughout nearly the entire duration of the cloud's passage, IMP 8 was located in the Earth's dawn magnetosheath providing observations of this cloud's interaction with the bow shock and magnetopause; the cloud is shown to maintain its solar wind characteristics during the interaction. Near the end of the cloud passage, at 0806 UT on December 17, ISEE 3 (and IMP 8 at nearly the same time) observed an oblique fast forward interplanetary shock closely coincident in time with a geomagnetic storm sudden commencement. The shock, moving much faster than the cloud (radial speeds of 700 and 390 km/s, respectively, on the average), was in the process of overtaking the cloud. The index Dst decreased monotonically by ∼ 130 nT during the 2-day cloud passage by the Earth and was well correlated with the B z component of the interplanetary magnetic field. There was no significant decrease in the cosmic ray intensity recorded by ground-based neutron monitors at this time of rather strong, smoothly changing fields. However, a Forbush decrease did occur immediately after the interplanetary shock, during a period of significant field turbulence. Thus a large, smooth, interplanetary helical magnetic field configuration engulfing the Earth does not necessarily deflect cosmic rays sufficiently to cause a Forbush decrease, but there is a suggestion that such a decrease may be caused by particle scattering by turbulent magnetic fields

  6. The Geomagnetically Induced Currents at the Equator Associated with Interplanetary Shocks

    Science.gov (United States)

    Yizengaw, E.; Doherty, P.; Carter, B. A.

    2016-12-01

    The arrival of interplanetary shocks drives magnetosphere and ionosphere current systems, which then can cause magnetic field variability at ground. The strength of these currents can be detected by the time derivation of the magnetometer observation (dB/dt) on the ground. The stronger dB/dt magnetic spikes at the arrival of interplanetary shocks may be able to cause significant geomagnetically induced currents (GIC) and electric fields that may have damaging effects on modern ground-based technological infrastructures. Although significant attention has been given to the impact of GICs at high-latitude regions, mainly in the auroral region where it gets amplified by the auroral electroject (AE), its impact at the geomagnetic equator has been largely overlooked until recently. It is well known that the interplanetary shocks-driven magnetopause current penetrates into the inner-magnetosphere and almost instantaneously extends down to the equatorial ionosphere through the TM0 (zero order transverse magnetic) mode waves in the Earth-ionosphere waveguide. These currents, which get amplified by the equatorial electroject (EEJ) in the same way the AE does to it, can cause bursts of GIC onto the power lines that are located in the vicinity of geomagnetic equator. Importantly, there are many cases in which interplanetary shocks that drive strong magnetopause currents sometimes do not cause geomagnetic storms and are followed by completely quiet conditions. This indicates that significant GIC can occur at high and equatorial regions not only during geomagnetic storm time but also during geomagnetically quiet periods. In this paper, using ground- and space-based observations, we demonstrate that the interplanetary shocks driven GIC bursts have potential effects at the equatorial region both during geomagnetically quiet and storm periods.

  7. Conceptual Grounds of Navigation Safety

    Directory of Open Access Journals (Sweden)

    Vladimir Torskiy

    2016-04-01

    Full Text Available The most important global problem being solved by the whole world community nowadays is to provide sustainable mankind development. Recent research in the field of sustainable development states that civilization safety is impossible without transfer sustainable development. At the same time, sustainable development (i.e. preservation of human culture and biosphere is impossible as a system that serves to meet economical, cultural, scientific, recreational and other human needs without safety. Safety plays an important role in sustainable development goals achievement. An essential condition of effective navigation functioning is to provide its safety. The “prescriptive” approach to the navigation safety, which is currently used in the world maritime field, is based on long-term experience and ship accidents investigation results. Thus this approach acted as an the great fact in reduction of number of accidents at sea. Having adopted the International Safety Management Code all the activities connected with navigation safety problems solution were transferred to the higher qualitative level. Search and development of new approaches and methods of ship accidents prevention during their operation have obtained greater importance. However, the maritime safety concept (i.e. the different points on ways, means and methods that should be used to achieve this goal hasn't been formed and described yet. The article contains a brief review of the main provisions of Navigation Safety Conceptions, which contribute to the number of accidents and incidents at sea reduction.

  8. Surgical navigation with QR codes

    Directory of Open Access Journals (Sweden)

    Katanacho Manuel

    2016-09-01

    Full Text Available The presented work is an alternative to established measurement systems in surgical navigation. The system is based on camera based tracking of QR code markers. The application uses a single video camera, integrated in a surgical lamp, that captures the QR markers attached to surgical instruments and to the patient.

  9. Semantic Characterizations of Navigational XPath

    NARCIS (Netherlands)

    Marx, M.J.; de Rijke, M.

    2005-01-01

    We give semantic characterizations of the expressive power of navigational XPath (a.k.a. Core XPath) in terms of first order logic. XPath can be used to specify sets of nodes and sets of paths in an XML document tree. We consider both uses. For sets of nodes, XPath is equally expressive as first

  10. Semantic characterizations of navigational XPath

    NARCIS (Netherlands)

    Marx, M.J.; de Rijke, M.; Mihajlovic, V.; Hiemstra, D.

    2004-01-01

    We give semantic characterizations of the expressive powerof navigational XPath (also called Core XPath) in terms offirst order logic. XPath can be used to specify sets of nodesand to specify sets of paths in a document tree. We considerboth uses. For sets of nodes, we show that first orderlogic in

  11. Celestial navigation in a nutshell

    CERN Document Server

    Schlereth, Hewitt

    2000-01-01

    Celestial Navigation in a Nutshell demonstrates how to take sights by the sun, moon, stars, and planets, discussing the advantages and disadvantages of each method. The reader is taken carefully through several examples and situational illustrations, making this a most effective self-teaching guide. Common errors are reviewed and several tips on how to improve accuracy are given.

  12. Designing automated handheld navigation support

    NARCIS (Netherlands)

    Uluca, D.; Streefkerk, J.W.; Sciacchitano, B.; McCrickard, D.S.

    2008-01-01

    Map usage on handheld devices suffers from limited screen size and the minimal attention that users can dedicate to them in mobile situations. This work examines effects of automating navigation features like zooming and panning as well as other features such as rotation, path finding and artifact

  13. Navigation in Cross-cultural business relationships

    DEFF Research Database (Denmark)

    Andersen, Poul Houman

    2001-01-01

    Cross-cultural business navigation concerns the process of handling the complexity of several interacting cultural spheres of influence......Cross-cultural business navigation concerns the process of handling the complexity of several interacting cultural spheres of influence...

  14. Shape Perception and Navigation in Blind Adults

    OpenAIRE

    Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

    2017-01-01

    Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of t...

  15. Navigation system for interstitial brachytherapy

    International Nuclear Information System (INIS)

    Strassmann, G.; Kolotas, C.; Heyd, R.

    2000-01-01

    The purpose of the stud was to develop a computed tomography (CT) based electromagnetic navigation system for interstitial brachytherapy. This is especially designed for situations when needles have to be positioned adjacent to or within critical anatomical structures. In such instances interactive 3D visualisation of the needle positions is essential. The material consisted of a Polhemus electromagnetic 3D digitizer, a Pentium 200 MHz laptop and a voice recognition for continuous speech. In addition, we developed an external reference system constructed of Perspex which could be positioned above the tumour region and attached to the patient using a non-invasive fixation method. A specially designed needle holder and patient bed were also developed. Measurements were made on a series of phantoms in order to study the efficacy and accuracy of the navigation system. The mean navigation accuracy of positioning the 20.0 cm length metallic needles within the phantoms was in the range 2.0-4.1 mm with a maximum of 5.4 mm. This is an improvement on the accuracy of a CT-guided technique which was in the range 6.1-11.3 mm with a maximum of 19.4 mm. The mean reconstruction accuracy of the implant geometry was 3.2 mm within a non-ferromagnetic environment. We found that although the needles were metallic this did not have a significant influence. We also found for our experimental setups that the CT table and operation table non-ferromagnetic parts had no significant influence on the navigation accuracy. This navigation system will be a very useful clinical tool for interstitial brachytherapy applications, particularly when critical structures have to be avoided. It also should provide a significant improvement on our existing technique

  16. 77 FR 42637 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Corrections

    Science.gov (United States)

    2012-07-20

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 84 and 115 [Docket No. USCG-2012-0306] RIN 1625-AB86 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments...), the Coast Guard published a final rule entitled ``Navigation and Navigable Waters; Technical...

  17. 32 CFR 644.3 - Navigation Projects.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Navigation Projects. 644.3 Section 644.3 National... HANDBOOK Project Planning Civil Works § 644.3 Navigation Projects. (a) Land to be acquired in fee. All... construction and borrow areas. (3) In navigation-only projects, the right to permanently flood should be...

  18. Global Navigation Satellite System and Augmentation

    Indian Academy of Sciences (India)

    Global Navigation Satellite System (GNSS) is a generic name given to a group of several satellite constellations such as the. Global Positioning System (GPS), GLObal NAvigation Satellite. System (GLONASS), Galileo, and Compass. The satellite con- stellations (navigation satellites) broadcast their positions and tim-.

  19. Sniffing Around for Providing Navigation Assistance

    NARCIS (Netherlands)

    Herder, E.

    2004-01-01

    In this paper we describe an approach to adaptive navigation assistance that is meant to enhance a user’s information scent. The navigation assistance is composed of a combination of predictive user navigation modeling and common information retrieval methods. Besides assistance in forward browsing,

  20. Global Optimization of Interplanetary Missions with, Hybrid Propulsion, Multi-Stage Spacecraft, Aerocapture, and Planetary Atmospheric Probes

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this IRAD is to expand the capability of Goddard’s interplanetary trajectory preliminary design tool, the Evolutionary Mission Trajectory Generator...

  1. 33 CFR 209.200 - Regulations governing navigable waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Regulations governing navigable waters. 209.200 Section 209.200 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.200 Regulations governing navigable waters...

  2. 33 CFR 67.35-10 - Private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Private aids to navigation. 67.35-10 Section 67.35-10 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS... Private aids to navigation. See § 67.15-10(b) for review of applications respecting private aids to...

  3. A Free-Return Earth-Moon Cycler Orbit for an Interplanetary Cruise Ship

    Science.gov (United States)

    Genova, Anthony L.; Aldrin, Buzz

    2015-01-01

    A periodic circumlunar orbit is presented that can be used by an interplanetary cruise ship for regular travel between Earth and the Moon. This Earth-Moon cycler orbit was revealed by introducing solar gravity and modest phasing maneuvers (average of 39 m/s per month) which yields close-Earth encounters every 7 or 10 days. Lunar encounters occur every 26 days and offer the chance for a smaller craft to depart the cycler and enter lunar orbit, or head for a Lagrange point (e.g., EM-L2 halo orbit), distant retrograde orbit (DRO), or interplanetary destination such as a near-Earth object (NEO) or Mars. Additionally, return-to-Earth abort options are available from many points along the cycling trajectory.

  4. Correlated variations in the azimuthal and elevation angles of the interplanetary magnetic field

    Science.gov (United States)

    Murphy, N.; Smith, E. J.; Goldstein, B.; Balogh, A.; Forsyth, R. J.

    1995-01-01

    Analysis of data collected during the in-ecliptic phase of the Ulysses mission shows that there are periods during which deviations from the Parker spiral direction in the azimuthal and elevation angles of the interplanetary magnetic field are correlated. There are a number of solar wind structures which might be expected to introduce such a correlation into the data, e.g., CMEs, Stream-stream interfaces or helicity carried by the solar wind. These potential sources fall into two categories: Those produced at or close to the solar wind source region and those produced by extended interactions as the solar wind expands. We will distinguish the contributions of these two source categories and assess the impact on the evolution on the interplanetary magnetic field.

  5. Estimating the Effects of Astronaut Career Ionizing Radiation Dose Limits on Manned Interplanetary Flight Programs

    Science.gov (United States)

    Koontz, Steven L.; Rojdev, Kristina; Valle, Gerard D.; Zipay, John J.; Atwell, William S.

    2013-01-01

    The Hybrid Inflatable DSH combined with electric propulsion and high power solar-electric power systems offer a near TRL-now solution to the space radiation crew dose problem that is an inevitable aspect of long term manned interplanetary flight. Spreading program development and launch costs over several years can lead to a spending plan that fits with NASA's current and future budgetary limitations, enabling early manned interplanetary operations with space radiation dose control, in the near future while biomedical research, nuclear electric propulsion and active shielding research and development proceed in parallel. Furthermore, future work should encompass laboratory validation of HZETRN calculations, as previous laboratory investigations have not considered large shielding thicknesses and the calculations presented at these thicknesses are currently performed via extrapolation.

  6. Polar solar wind and interstellar wind properties from interplanetary Lyman-alpha radiation measurements

    Science.gov (United States)

    Witt, N.; Blum, P. W.; Ajello, J. M.

    1981-01-01

    The analysis of Mariner 10 observations of Lyman-alpha resonance radiation shows an increase of interplanetary neutral hydrogen densities above the solar poles. This increase is caused by a latitudinal variation of the solar wind velocity and/or flux. Using both the Mariner 10 results and other solar wind observations, the values of the solar wind flux and velocity with latitude are determined for several cases of interest. The latitudinal variation of interplanetary hydrogen gas, arising from the solar wind latitudinal variation, is shown to be most pronounced in the inner solar system. From this result it is shown that spacecraft Lyman-alpha observations are more sensitive to the latitudinal anisotropy for a spacecraft location in the inner solar system near the downwind axis.

  7. Mid-Infrared Spectrum of the Zodiacal Emission: Detection of Crystalline Silicates in Interplanetary Dust

    Science.gov (United States)

    Ootsubo, T.; Onaka, T.; Yamamura, I.; Ishihara, D.; Tanabe, T.; Roellig, T. L.

    2003-01-01

    Within a few astronomical units of the Sun the solar system is filled with interplanetary dust, which is believed to be dust of cometary and asteroidal origin. Spectroscopic observations of the zodiacal emission with moderate resolution provide key information on the composition and size distribution of the dust in the interplanetary space. They can be compared directly to laboratory measurements of candidate materials, meteorites, and dust particles collected in the stratosphere. Recently mid-infrared spectroscopic observations of the zodiacal emission have been made by two instruments on board the Infrared Space Observatory; the camera (ISOCAM) and the spectrophotometer (ISOPHOT-S). A broad excess emission feature in the 9-11 micron range is reported in the ISOCAM spectrum, whereas the ISOPHOT-S spectra in 6-12 microns can be well fitted by a blackbody radiation without spectral features.

  8. Interplanetary and Interstellar Dust Observed by the Wind/WAVES Electric Field Instrument

    Science.gov (United States)

    Malaspina, David; Horanyi, M.; Zaslavsky, A.; Goetz, K.; Wilson, L. B., III; Kersten, K.

    2014-01-01

    Observations of hypervelocity dust particles impacting the Wind spacecraft are reported here for the first time using data from the WindWAVES electric field instrument. A unique combination of rotating spacecraft, amplitude-triggered high-cadence waveform collection, and electric field antenna configuration allow the first direct determination of dust impact direction by any spacecraft using electric field data. Dust flux and impact direction data indicate that the observed dust is approximately micron-sized with both interplanetary and interstellar populations. Nanometer radius dust is not detected by Wind during times when nanometer dust is observed on the STEREO spacecraft and both spacecraft are in close proximity. Determined impact directions suggest that interplanetary dust detected by electric field instruments at 1 AU is dominated by particles on bound trajectories crossing Earths orbit, rather than dust with hyperbolic orbits.

  9. European global navigation satellite launches

    Science.gov (United States)

    Zielinski, Sarah

    The European Space Agency launched its first Galileo satellite on 28 December 2005.When fully deployed, the Galileo system will provide a European global navigation alternative to the U.S. global positioning system (GPS) and the Russian global navigation satellite system (Glonass).The Galileo system will consist of 30 satellites (27 operational plus three active spare satellites) that are scheduled to be launched and fully operational by the end of 2008.The system will provide real-time positioning within one meter of accuracy and be fully inter-operable with the U.S. and Russian systems. However, unlike GPS and Glonass, Galileo will be under civilian rather than military control.

  10. Navigating the Internet of Things

    DEFF Research Database (Denmark)

    Rassia, Stamatina; Steiner, Henriette

    2017-01-01

    Navigating the Internet of Things is an exploration of interconnected objects, functions, and situations in networks created to ease and manage our daily lives. The Internet of Things represents semi-automated interconnections of different objects in a network based on different information...... technologies. Some examples of this are presented here in order to better understand, explain, and discuss the elements that compose the Internet of Things. In this chapter, we provide a theoretical and practical perspective on both the micro- and macro-scales of ‘things’ (objects), small and large (e.......g. computers or interactive maps), that suggest new topographic relationships and challenge our understanding of users’ involvement with a given technology against the semi-automated workings of these systems. We navigate from a philosophical enquiry into the ‘thingness of things’ dating from the 1950s...

  11. High-latitude ionospheric convection during strong interplanetary magnetic field B-y

    DEFF Research Database (Denmark)

    Huang, C.S.; Sofko, G.J.; Murr, D.

    1999-01-01

    . The interplanetary magnetic field (IMF) conditions corresponding to the occurrence of the ionospheric convection were B-x approximate to 1 nT, B-y approximate to 10 nT, and B-z ...An unusual high-latitude ionospheric pattern was observed on March 23, 1995. ionospheric convection appeared as clockwise merging convection cell focused at 84 degrees magnetic latitude around 1200 MLT. No signature of the viscous convection cell in the afternoon sector was observed...

  12. Strong geomagnetic activity forecast by neural networks under dominant southern orientation of the interplanetary magnetic field

    Czech Academy of Sciences Publication Activity Database

    Valach, F.; Bochníček, Josef; Hejda, Pavel; Revallo, M.

    2014-01-01

    Roč. 53, č. 4 (2014), s. 589-598 ISSN 0273-1177 R&D Projects: GA AV ČR(CZ) IAA300120608; GA MŠk OC09070 Institutional support: RVO:67985530 Keywords : geomagnetic activity * interplanetary magnetic field * artificial neural network * ejection of coronal mass * X-ray flares Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 1.358, year: 2014

  13. An analysis of interplanetary scintillation as a method of measuring the angular sizes of radio sources

    International Nuclear Information System (INIS)

    Hajivassiliou, C.A.; Duffett-Smith, P.J.

    1990-01-01

    Interplanetary scintillation has been widely used at metre wavelengths for estimating the angular sizes of radio sources in the range 0.1-2.0 arcsec. The estimates are based on observations of either the width of the temporal power spectrum or the shape of the scintillation index-elongation curve. We present a mathematical model of the latter procedure which reveals the biases introduced into an IPS survey as a result of the estimation process. (author)

  14. ED navigators prevent unnecessary admissions.

    Science.gov (United States)

    2012-02-01

    RN Navigators in the emergency department at Montefiore Medical Center work with social workers to prevent unnecessary admissions. Program targets the homeless and patients with tenuous living situations. CMs work with the emergency department staff to identify patients who don't meet admission criteria but can't be safely discharged. The hospital collaborates with a local housing assistance agency which sends a van to transport appropriate patients to a shelter.

  15. Outdoor navigation of mobile robots

    OpenAIRE

    Mäkelä, Hannu

    2001-01-01

    AGVs in the manufacturing industry currently constitute the largest application area for mobile robots. Other applications have been gradually emerging, including various transporting tasks in demanding environments, such as mines or harbours. Most of the new potential applications require a free-ranging navigation system, which means that the path of a robot is no longer bound to follow a buried inductive cable. Moreover, changing the route of a robot or taking a new working area into use mu...

  16. Spatial navigation in young versus older adults

    Directory of Open Access Journals (Sweden)

    Ivana eGazova

    2013-12-01

    Full Text Available Older age is associated with changes in the brain, including the medial temporal lobe, which may result in mild spatial navigation deficits, especially in allocentric navigation. The aim of the study was to characterize the profile of real-space allocentric (world-centered, hippocampus dependent and egocentric (body-centered, parietal lobe dependent navigation and learning in young vs. older adults, and to assess a possible influence of gender. We recruited healthy participants without cognitive deficits on standard neuropsychological testing, white matter lesions or pronounced hippocampal atrophy: 24 young participants (18-26 years old and 44 older participants stratified as participants 60-70 years old (n=24 and participants 71-84 years old (n=20. All underwent spatial navigation testing in the real-space human analog of the Morris Water Maze, which has the advantage of assessing separately allocentric and egocentric navigation and learning. Of the 8 consecutive trials, trials 2-8 were used to reduce bias by a rebound effect (more dramatic changes in performance between trials 1 and 2 relative to subsequent trials. The participants who were 71-84 years old (p< .001, but not those 60-70 years old, showed deficit in allocentric navigation compared to the young participants. There were no differences in egocentric navigation. All three groups showed spatial learning effect (p´s ≤.01. There were no gender differences in spatial navigation and learning. The linear regression limited to older participants showed linear (β=0.30, p=.045 and quadratic (β=0.30, p=.046 effect of age on allocentric navigation. There was no effect of age on egocentric navigation. These results demonstrate that navigation deficits in older age may be limited to allocentric navigation, whereas egocentric navigation and learning may remain preserved. This specific pattern of spatial navigation impairment may help differentiate normal aging from prodromal Alzheimer

  17. Navigation in diagnosis and therapy

    International Nuclear Information System (INIS)

    Vannier, Michael W.; Haller, John W.

    1999-01-01

    Image-guided navigation for surgery and other therapeutic interventions has grown in importance in recent years. During image-guided navigation a target is detected, localized and characterized for diagnosis and therapy. Thus, images are used to select, plan, guide and evaluate therapy, thereby reducing invasiveness and improving outcomes. A shift from traditional open surgery to less-invasive image-guided surgery will continue to impact the surgical marketplace. Increases in the speed and capacity of computers and computer networks have enabled image-guided interventions. Key elements in image navigation systems are pre-operative 3D imaging (or real-time image acquisition), a graphical display and interactive input devices, such as surgical instruments with light emitting diodes (LEDs). CT and MRI, 3D imaging devices, are commonplace today and 3D images are useful in complex interventions such as radiation oncology and surgery. For example, integrated surgical imaging workstations can be used for frameless stereotaxy during neurosurgical interventions. In addition, imaging systems are being expanded to include decision aids in diagnosis and treatment. Electronic atlases, such as Voxel Man or others derived from the Visible Human Project, combine a set of image data with non-image knowledge such as anatomic labels. Robot assistants and magnetic guidance technology are being developed for minimally invasive surgery and other therapeutic interventions. Major progress is expected at the interface between the disciplines of radiology and surgery where imaging, intervention and informatics converge

  18. The Cubesat mission to study Solar Particles (CuSP), an interplanetary cubesat

    Science.gov (United States)

    Christian, E. R.; Desai, M. I.; Allegrini, F.; Jahn, J. M.; Kanekal, S.; Livi, S. A.; Murphy, N.; Ogasawara, K.; Paschalidis, N.

    2015-12-01

    The Cubesat mission to study Solar Particles (CuSP) is a funded 6U interplanetary cubesat scheduled to fly on the EM-1 SLS launch in 2018. CuSP has three small but capable instruments from the Southwest Research Institute (SwRI), NASA Goddard Space Flight Center (GSFC), and the NASA Jet Propulsion Laboratory (JPL). Its primary scientific goal is high-cadence precise measurements of the suprathermal (ST) tail in the solar wind. The suprathermal tail is the critical bridge between the thermal solar wind plasma and the dangerous high-energy solar energetic particles. CuSP also measures the energy spectra and composition of the ~1-50 MeV/nucleon H-Fe ions that evolve from the STs and the interplanetary magnetic field that is closely coupled to the particle distributions. CuSP is a stepping-stone to future interplanetary cubesats, smallsats, and constellations for both scientific and space weather applications. The challenges for this mission and future missions will also be discussed.

  19. Drag derived altitude aided navigation method

    Directory of Open Access Journals (Sweden)

    Hua SONG

    2017-10-01

    Full Text Available The navigation problem of the lifting reentry vehicles has attracted much research interest in the past decade. This paper researches the navigation in the blackout zone during the reentry phase of the aircraft, when the communication signals are attenuated and even interrupted by the blackout zone. However, when calculating altitude, a pure classic inertial navigation algorithm appears imprecise and divergent. In order to obtain a more precise aircraft altitude, this paper applies an integrated navigation method based on inertial navigation algorithms, which uses drag derived altitude to aid the inertial navigation during the blackout zone. This method can overcome the shortcomings of the inertial navigation system and improve the navigation accuracy. To further improve the navigation accuracy, the applicable condition and the main error factors, such as the atmospheric coefficient error and drag coefficient error are analyzed in detail. Then the damping circuit design of the navigation control system and the damping coefficients determination is introduced. The feasibility of the method is verified by the typical reentry trajectory simulation, and the influence of the iterative times on the accuracy is analyzed. Simulation results show that iterative three times achieves the best effect.

  20. Navigation Operations for the Magnetospheric Multiscale Mission

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  2. Navigation.

    Science.gov (United States)

    Wellman, Bruce; Lipton, Laura

    2000-01-01

    Teachers' quests for more data-based planning, problem solving, and decision making often stumble against limited capacities for engaging in thoughtful interactions, with groups typically lacking process tools, collaborative communication skills, and reflective habits. This article presents a three-phase model for guiding data-driven dialogue in…

  3. Autonomous Robot Navigation based on Visual Landmarks

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    The use of landmarks for robot navigation is a popular alternative to having a geometrical model of the environment through which to navigate and monitor self-localization. If the landmarks are defined as special visual structures already in the environment then we have the possibility of fully...... autonomous navigation and self-localization using automatically selected landmarks. The thesis investigates autonomous robot navigation and proposes a new method which benefits from the potential of the visual sensor to provide accuracy and reliability to the navigation process while relying on naturally...... update of the estimated robot position while the robot is moving. In order to make the system autonomous, both acquisition and observation of landmarks have to be carried out automatically. The thesis consequently proposes a method for learning and navigation of a working environment and it explores...

  4. Indoor inertial waypoint navigation for the blind.

    Science.gov (United States)

    Riehle, Timothy H; Anderson, Shane M; Lichter, Patrick A; Whalen, William E; Giudice, Nicholas A

    2013-01-01

    Indoor navigation technology is needed to support seamless mobility for the visually impaired. This paper describes the construction and evaluation of an inertial dead reckoning navigation system that provides real-time auditory guidance along mapped routes. Inertial dead reckoning is a navigation technique coupling step counting together with heading estimation to compute changes in position at each step. The research described here outlines the development and evaluation of a novel navigation system that utilizes information from the mapped route to limit the problematic error accumulation inherent in traditional dead reckoning approaches. The prototype system consists of a wireless inertial sensor unit, placed at the users' hip, which streams readings to a smartphone processing a navigation algorithm. Pilot human trials were conducted assessing system efficacy by studying route-following performance with blind and sighted subjects using the navigation system with real-time guidance, versus offline verbal directions.

  5. Spatial Database Modeling for Indoor Navigation Systems

    Science.gov (United States)

    Gotlib, Dariusz; Gnat, Miłosz

    2013-12-01

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

  6. INS/CNS/GNSS integrated navigation technology

    CERN Document Server

    Quan, Wei; Gong, Xiaolin; Fang, Jiancheng

    2015-01-01

    This book not only introduces the principles of INS, CNS and GNSS, the related filters and semi-physical simulation, but also systematically discusses the key technologies needed for integrated navigations of INS/GNSS, INS/CNS, and INS/CNS/GNSS, respectively. INS/CNS/GNSS integrated navigation technology has established itself as an effective tool for precise positioning navigation, which can make full use of the complementary characteristics of different navigation sub-systems and greatly improve the accuracy and reliability of the integrated navigation system. The book offers a valuable reference guide for graduate students, engineers and researchers in the fields of navigation and its control. Dr. Wei Quan, Dr. Jianli Li, Dr. Xiaolin Gong and Dr. Jiancheng Fang are all researchers at the Beijing University of Aeronautics and Astronautics.

  7. Emergency Navigation without an Infrastructure

    Directory of Open Access Journals (Sweden)

    Erol Gelenbe

    2014-08-01

    Full Text Available Emergency navigation systems for buildings and other built environments, such as sport arenas or shopping centres, typically rely on simple sensor networks to detect emergencies and, then, provide automatic signs to direct the evacuees. The major drawbacks of such static wireless sensor network (WSN-based emergency navigation systems are the very limited computing capacity, which makes adaptivity very difficult, and the restricted battery power, due to the low cost of sensor nodes for unattended operation. If static wireless sensor networks and cloud-computing can be integrated, then intensive computations that are needed to determine optimal evacuation routes in the presence of time-varying hazards can be offloaded to the cloud, but the disadvantages of limited battery life-time at the client side, as well as the high likelihood of system malfunction during an emergency still remain. By making use of the powerful sensing ability of smart phones, which are increasingly ubiquitous, this paper presents a cloud-enabled indoor emergency navigation framework to direct evacuees in a coordinated fashion and to improve the reliability and resilience for both communication and localization. By combining social potential fields (SPF and a cognitive packet network (CPN-based algorithm, evacuees are guided to exits in dynamic loose clusters. Rather than relying on a conventional telecommunications infrastructure, we suggest an ad hoc cognitive packet network (AHCPN-based protocol to adaptively search optimal communication routes between portable devices and the network egress nodes that provide access to cloud servers, in a manner that spares the remaining battery power of smart phones and minimizes the time latency. Experimental results through detailed simulations indicate that smart human motion and smart network management can increase the survival rate of evacuees and reduce the number of drained smart phones in an evacuation process.

  8. Emergency navigation without an infrastructure.

    Science.gov (United States)

    Gelenbe, Erol; Bi, Huibo

    2014-08-18

    Emergency navigation systems for buildings and other built environments, such as sport arenas or shopping centres, typically rely on simple sensor networks to detect emergencies and, then, provide automatic signs to direct the evacuees. The major drawbacks of such static wireless sensor network (WSN)-based emergency navigation systems are the very limited computing capacity, which makes adaptivity very difficult, and the restricted battery power, due to the low cost of sensor nodes for unattended operation. If static wireless sensor networks and cloud-computing can be integrated, then intensive computations that are needed to determine optimal evacuation routes in the presence of time-varying hazards can be offloaded to the cloud, but the disadvantages of limited battery life-time at the client side, as well as the high likelihood of system malfunction during an emergency still remain. By making use of the powerful sensing ability of smart phones, which are increasingly ubiquitous, this paper presents a cloud-enabled indoor emergency navigation framework to direct evacuees in a coordinated fashion and to improve the reliability and resilience for both communication and localization. By combining social potential fields (SPF) and a cognitive packet network (CPN)-based algorithm, evacuees are guided to exits in dynamic loose clusters. Rather than relying on a conventional telecommunications infrastructure, we suggest an ad hoc cognitive packet network (AHCPN)-based protocol to adaptively search optimal communication routes between portable devices and the network egress nodes that provide access to cloud servers, in a manner that spares the remaining battery power of smart phones and minimizes the time latency. Experimental results through detailed simulations indicate that smart human motion and smart network management can increase the survival rate of evacuees and reduce the number of drained smart phones in an evacuation process.

  9. Youth Mobilisation as Social Navigation

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2010-01-01

    This article sheds light on the mobilisation of young people into conflict. It argues that warfare constitutes a terrain of possibility for urban youth in Guinea‑Bissau, and shows how they navigate war as an event by tactically manoeuvring within the social ties and options that arise in such sit...

  10. Research on integrated navigation method for AUV

    Science.gov (United States)

    Guo, Zhen; Sun, Feng

    2005-06-01

    The principles of the SINS/DVL integrated navigation system are introduced, and the compass status accuracy is compared. When the heading is changed, the dead reckoning algorithm using the heading information of the SINS (Strapdown inertial navigation systems) and DVL (doppler velocity log) is adopted to substitute the SINS/DVL integrated system. The simulation results show that the method can improve the accuracy of integrated navigation system when AUV (autonomous underwater vehicle) is in motion.

  11. Global navigation satellite systems and their applications

    CERN Document Server

    Madry, Scott

    2015-01-01

    Dr. Madry, one of the world's leading experts in the field, provides in a condensed form a quick yet comprehensive overview of satellite navigation. This book concisely addresses the latest technology, the applications, the regulatory issues, and the strategic implications of satellite navigation systems. This assesses the strengths and weaknesses of satellite navigation networks and review of all the various national systems now being deployed and the motivation behind the proliferation of these systems.

  12. Reconstruction of geomagnetic activity and near-Earth interplanetary conditions over the past 167 yr – Part 2: A new reconstruction of the interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Lockwood

    2013-11-01

    Full Text Available We present a new reconstruction of the interplanetary magnetic field (IMF, B for 1846–2012 with a full analysis of errors, based on the homogeneously constructed IDV(1d composite of geomagnetic activity presented in Part 1 (Lockwood et al., 2013a. Analysis of the dependence of the commonly used geomagnetic indices on solar wind parameters is presented which helps explain why annual means of interdiurnal range data, such as the new composite, depend only on the IMF with only a very weak influence of the solar wind flow speed. The best results are obtained using a polynomial (rather than a linear fit of the form B = χ · (IDV(1d − βα with best-fit coefficients χ = 3.469, β = 1.393 nT, and α = 0.420. The results are contrasted with the reconstruction of the IMF since 1835 by Svalgaard and Cliver (2010.

  13. The Effects Of Age, Spatial Ability, And Navigational Information On Navigational Performance

    Science.gov (United States)

    1995-12-01

    THE PURPOSE OF THE STUDY REPORTED HERE WAS TO EXAMINE WHETHER AGE AND SPATIAL ABILITY ARE FACTORS THAT INFLUENCE A DRIVER'S ABILITY TO NAVIGATE AND TO USE NAVIGATIONAL DISPLAYS. THESE FACTORS WERE EXAMINED BECAUSE PREVIOUS : RESEARCH SUGGESTS THAT SP...

  14. 77 FR 37305 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments

    Science.gov (United States)

    2012-06-21

    ... Fishing vessels, Navigation (water), Waterways. 33 CFR Part 100 Marine safety, Navigation (water... practice and procedure, Advertising, Claims, Oil pollution, Penalties, Reporting and recordkeeping requirements. 33 CFR Part 138 Hazardous materials transportation, Insurance, Oil pollution, Reporting and...

  15. Instruments and method of air navigation

    Science.gov (United States)

    1977-01-01

    Topics discussed include magnetic and astronavigation instruments; flight beyond ground visibility; aircraft radio navigation instruments and communication radio sets; instrument landing systems; and ground controlled landing systems.

  16. Review of intelligent bionic vision navigation

    Science.gov (United States)

    Wu, Peng; Mu, Rongjun; Deng, Yanpeng

    2017-11-01

    With the popularization of intelligent equipment such as UAV (Unmanned Aerial Vehicle) and UV (Unmanned Vehicle), their demands for autonomy, independence and intelligence of navigation gradually increase, and traditional navigation methods can't meet this demand. In order to make a thorough study, a review of intelligent bionic vision navigation methods is made on its background, research status and related fields. Through the analysis and summarization of the above information, the development trend of intelligent bionic vision navigation is pointed out, and its advantages and disadvantages are discussed.

  17. Hybrid Guidance System for Relative Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA architectures and missions will involve many distributed platforms that must work together. This in turn requires guidance, navigation and control...

  18. ATTREX-Aircraft_navigational_and_meteorological_Measurements

    Data.gov (United States)

    National Aeronautics and Space Administration — This collection consists of the observational data from the Airborne Tropical TRopopause EXperiment (ATTREX) aircraft navigational and meteorological measurements...

  19. Robotics_MobileRobot Navigation, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Robots and rovers exploring planets need to autonomously navigate to specified locations. Advanced Scientific Concepts, Inc. (ASC) and the University of Minnesota...

  20. Airports and Navigation Aids Database System -

    Data.gov (United States)

    Department of Transportation — Airport and Navigation Aids Database System is the repository of aeronautical data related to airports, runways, lighting, NAVAID and their components, obstacles, no...

  1. Intelligent navigation and multivehicle coordination

    Science.gov (United States)

    McKay, Mark D.; Anderson, Matthew O.; Kinoshita, Robert A.; Flann, Nicholas S.

    1999-07-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) and Utah State University's Center for Self-Organizing and Intelligent Systems have developed a team of autonomous robotic vehicles. This paper discusses the development of a strategy that uses a sophisticated, highly intelligent sensor platform to allow centralized coordination between smaller and inexpensive robots. The three components of the multi-agent cooperative scheme are small-scale robots, large-scale robots, and the central control station running a mission and path- planning software. The smaller robots are used for activities where the probability of loss increases, such as Unexploded Ordnance (UXO) or mine detonation. The research is aimed at building simple, inexpensive multi-agent vehicles and an intelligent navigation and multi-vehicle coordination system suitable for UXO, environmental remediation or mine detection. These simplified robots are capable of conducting hunting missions using low-cost positioning sensors and intelligent algorithms. Additionally, a larger sensor-rich intelligent system capable of transporting smaller units to outlying remote sites has been developed. The larger system interfaces to the central control station and provides navigation assistance to multiple low-cost vehicles. Finally, mission and path-planning software serves as the operator control unit, allowing central data collection, map creation and tracking, and an interface to the larger system as well as each smaller unit. The power of this scheme is the ability to scale to the appropriate level for the complexity of the mission.

  2. 33 CFR 183.810 - Navigation light certification requirements.

    Science.gov (United States)

    2010-07-01

    ...) Identification and specifications of the bulb used in the compliance test. (b) If a light is too small to attach... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Navigation light certification... SECURITY (CONTINUED) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Navigation Lights § 183.810 Navigation...

  3. 33 CFR 209.315 - Public access to navigation works.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Public access to navigation works..., DEPARTMENT OF DEFENSE ADMINISTRATIVE PROCEDURE § 209.315 Public access to navigation works. While the... navigation works of general public interest subject to the following criteria: (a) The public will not be...

  4. Off the Beaten tracks: Exploring Three Aspects of Web Navigation

    NARCIS (Netherlands)

    Weinreich, H.; Obendorf, H.; Herder, E.; Mayer, M.; Edmonds, H.; Hawkey, K.; Kellar, M.; Turnbull, D.

    2006-01-01

    This paper presents results of a long-term client-side Web usage study, updating previous studies that range in age from five to ten years. We focus on three aspects of Web navigation: changes in the distribution of navigation actions, speed of navigation and within-page navigation. “Navigation

  5. An Integrated Tool for Low Thrust Optimal Control Orbit Transfers in Interplanetary Trajectories

    Science.gov (United States)

    Dargent, T.; Martinot, V.

    In the last recent years a significant progress has been made in optimal control orbit transfers using low thrust electrical propulsion for interplanetary missions. The system objective is always the same: decrease the transfer duration and increase the useful satellite mass. The optimum control strategy to perform the minimum time to orbit or the minimum fuel consumption requires the use of sophisticated mathematical tools, most of the time dedicated to a specific mission and therefore hardly reusable. To improve this situation and enable Alcatel Space to perform rather quick trajectory design as requested by mission analysis, we have developed a software tool T-3D dedicated to optimal control orbit transfers which integrates various initial and terminal rendezvous conditions - e.g. fixed arrival time for planet encounter - and engine thrust profiles -e.g. thrust law variation with respect to the distance to the Sun -. This single and quite versatile tool allows to perform analyses like minimum consumption for orbit insertions around a planet from an hyperbolic trajectory, interplanetary orbit transfers, low thrust minimum time multiple revolution orbit transfers, etc… From a mathematical point of view, the software relies on the minimum principle formulation to find the necessary conditions of optimality. The satellite dynamics is a two body model and relies of an equinoctial formulation of the Gauss equation. This choice has been made for numerical purpose and to solve more quickly the two point boundaries values problem. In order to handle the classical problem of co-state variables initialization, problems simpler than the actual one can be solved straight forward by the tool and the values of the co-state variables are kept as first guess for a more complex problem. Finally, a synthesis of the test cases is presented to illustrate the capacities of the tool, mixing examples of interplanetary mission, orbit insertion, multiple revolution orbit transfers

  6. Interplanetary Trajectory Design for the Asteroid Robotic Redirect Mission Alternate Approach Trade Study

    Science.gov (United States)

    Merrill, Raymond Gabriel; Qu, Min; Vavrina, Matthew A.; Englander, Jacob A.; Jones, Christopher A.

    2014-01-01

    This paper presents mission performance analysis methods and results for the Asteroid Robotic Redirect Mission (ARRM) option to capture a free standing boulder on the surface of a 100 m or larger NEA. It details the optimization and design of heliocentric low-thrust trajectories to asteroid targets for the ARRM solar electric propulsion spacecraft. Extensive searches were conducted to determine asteroid targets with large pick-up mass potential and potential observation opportunities. Interplanetary trajectory approximations were developed in method based tools for Itokawa, Bennu, 1999 JU3, and 2008 EV5 and were validated by end-to-end integrated trajectories.

  7. Interplanetary conditions during 3-kHz radio-wave detections in the outer heliosphere

    Science.gov (United States)

    Lanzerotti, L. J.; Maclennan, C. G.; Gold, R. E.

    1985-01-01

    Plasma waves detected by the Voyager 1 and 2 spacecraft beyond about 12 AU that may be associated with the turbulence expected at the heliopause are interpreted in terms of the characteristics of the interplanetary medium at large heliocentric distances. The low-energy charged-particle environment in the outer heliosphere during the observations of the unusual plasma-wave signals is addressed. The particle data suggest that the outer heliosphere was unusually stable and free of transient shock and particle events for the roughly eight months during the wave observations.

  8. Interplanetary scintillations of the 3C 279 radiosource from RATAN-600 observations

    International Nuclear Information System (INIS)

    Shishova, T.D.; Mingaliev, M.G.; AN SSSR, Nizhnij Arkhyz. Spetsial'naya Astrofizicheskaya Observatoriya)

    1980-01-01

    In 1976 and 1977 observations of interplanetary scintillations of the 3C 279 radiosource were carred out at the RATAN-600 at centimeter wavelengths. At Lambda=3.9 cm the index of scintillations gets suturated at the distance R approximately equal to 4 Rsub(Sun) from the Sun. The estimation of solar wind velocity is approximately 140 km/s at R=5Rsub(Sun); it grows up to approximately 400 km/s at R approximately equal to 10 Rsub(Sun)

  9. Precise localizations and counterpart searches of GRBs from the 2nd interplanetary network

    International Nuclear Information System (INIS)

    Hack, F.; Hurley, K.; Atteia, J.; Barat, C.; Niel, M.; Cline, T.; Dennis, B.; Kouveliotou, C.; Klebesadel, R.; Laros, J.; Kurt, V.; Kuznetsov, A.; Zenchenko, V.

    1994-01-01

    The second interplanetary network of GRB detectors operated between 1981 and 1984. It consisted of the Venera 13 and V14 spacecraft (SIGNE detectors), PVO, ICE, and SMM (HXRBS detector). Many of the approximately 90 cosmic GRBs it detected can be localized to a high accuracy. Such localizations will make a better estimate of the burster recurrence time possible and contribute to the search for quiescent counterparts. We will present a number of localizations to illustrate the potential of this network, discuss the techniques we use to perform multi-wavelength counterpart searches, and compare present and promising future localization techniques

  10. New evidence for interplanetary boulders?. [photometric observations of cometary nuclei orbit perturbations

    Science.gov (United States)

    Sekanina, Z.

    1973-01-01

    The method of detection, the magnitude and the rate of occurrence of sudden disturbances in the motions of some short period comets are discussed. The disturbances have recently been suggested as potential indicators of collisions between the comets and interplanetary boulders - minor objects whose existence was predicted. The character of explosive phenomena, caused by an impact of such a boulder on a comet's nuclear surface, depends significantly on the surface texture of the target body. A method is suggested which supplies a good deal of the missing information about the structure and optical properties of nuclear surfaces from precise photometric observations of cometary nuclei at large solar distances.

  11. Overview of cosmic rays, solar and interplanetary physics research (1987-1990)

    Science.gov (United States)

    Jokipii, J. R.

    1991-01-01

    A brief survey of recent U.S. investigations in the field of heliospheric plasmas and their manifestations is presented, introducing the following collection of detailed reviews (accessions A91-46959 to A91-46964). Topics examined include the large-scale structure of interplanetary plasmas, models of Galactic cosmic-ray production and propagation, solar-wind turbulence, long-period solar-terrestrial variability, the possible relation between solar-neutrino counts and the sunspot cycle, X-ray studies of solar flares and their implications for solar processes, and the near-sun magnetic field.

  12. Mineralogy of Interplanetary Dust Particles from the Comet Giacobini-Zinner Dust Stream Collections

    Science.gov (United States)

    Nakamura-Messenger, K.; Messenger, S.; Westphal, A. J.; Palma, R. L.

    2015-01-01

    The Draconoid meteor shower, originating from comet 21P/Giacobini-Zinner, is a low-velocity Earth-crossing dust stream that had a peak anticipated flux on Oct. 8, 2012. In response to this prediction, NASA performed dedicated stratospheric dust collections to target interplanetary dust particles (IDPs) from this comet stream on Oct 15-17, 2012 [3]. Twelve dust particles from this targeted collection were allocated to our coordinated analysis team for studies of noble gas (Univ. Minnesota, Minnesota State Univ.), SXRF and Fe-XANES (SSL Berkeley) and mineralogy/isotopes (JSC). Here we report a mineralogical study of 3 IDPs from the Draconoid collection..

  13. Coronal type III radio bursts and their X-ray flare and interplanetary type III counterparts

    Science.gov (United States)

    Reid, Hamish A. S.; Vilmer, Nicole

    2017-01-01

    Context. Type III bursts and hard X-rays are both produced by flare energetic electron beams. The link between both emissions has been investigated in many previous studies, but no statistical studies have compared both coronal and interplanetary type III bursts with X-ray flares. Aims: Using events where the coronal radio emission above 100 MHz is exclusively from type III bursts, we revisited some long-standing questions regarding the relation between type III bursts and X-ray flares: Do all coronal type III bursts have X-ray counterparts? What correlation, if any, occurs between radio and X-ray intensities? What X-ray and radio signatures above 100 MHz occur in connection with interplanetary type III bursts below 14 MHz? Methods: We analysed ten years of data from 2002 to 2011 starting with a selection of coronal type III bursts above 100 MHz. We used X-ray flare information from RHESSI >6 keV to make a list of 321 events that have associated type III bursts and X-ray flares, encompassing at least 28% of the initial sample of type III events. We then examined the timings, intensities, associated GOES class, and whether there was an associated interplanetary radio signature in both radio and X-rays. Results: For our 321 events with radio and X-ray signatures, the X-ray emission at 6 keV usually lasted much longer than the groups of type III bursts at frequencies >100 MHz. The selected events were mostly associated with GOES B and C class flares. A weak correlation was found between the type III radio flux at frequencies below 327 MHz and the X-ray intensity at 25-50 keV, with an absence of events at high X-ray intensity and low type III radio flux. The weakness of the correlation is related to the coherent emission mechanism of radio type IIIs which can produce high radio fluxes by low density electron beams. Interplanetary type III bursts (103 SFU), relating to electron beams with more energetic electrons above 25 keV and events where magnetic flux tubes extend

  14. On the twists of interplanetary magnetic flux ropes observed at 1 AU

    Science.gov (United States)

    Wang, Yuming; Zhuang, Bin; Hu, Qiang; Liu, Rui; Shen, Chenglong; Chi, Yutian

    2016-10-01

    Magnetic flux ropes (MFRs) are one kind of fundamental structures in the solar/space physics and involved in various eruption phenomena. Twist, characterizing how the magnetic field lines wind around a main axis, is an intrinsic property of MFRs, closely related to the magnetic free energy and stableness. Although the effect of the twist on the behavior of MFRs had been widely studied in observations, theory, modeling, and numerical simulations, it is still unclear how much amount of twist is carried by MFRs in the solar atmosphere and in heliosphere and what role the twist played in the eruptions of MFRs. Contrasting to the solar MFRs, there are lots of in situ measurements of magnetic clouds (MCs), the large-scale MFRs in interplanetary space, providing some important information of the twist of MFRs. Thus, starting from MCs, we investigate the twist of interplanetary MFRs with the aid of a velocity-modified uniform-twist force-free flux rope model. It is found that most of MCs can be roughly fitted by the model and nearly half of them can be fitted fairly well though the derived twist is probably overestimated by a factor of 2.5. By applying the model to 115 MCs observed at 1 AU, we find that (1) the twist angles of interplanetary MFRs generally follow a trend of about 0.6l/R radians, where l/R is the aspect ratio of a MFR, with a cutoff at about 12π radians AU-1, (2) most of them are significantly larger than 2.5π radians but well bounded by 2l/R radians, (3) strongly twisted magnetic field lines probably limit the expansion and size of MFRs, and (4) the magnetic field lines in the legs wind more tightly than those in the leading part of MFRs. These results not only advance our understanding of the properties and behavior of interplanetary MFRs but also shed light on the formation and eruption of MFRs in the solar atmosphere. A discussion about the twist and stableness of solar MFRs are therefore given.

  15. The Inner Magnetosphere Plasma Response to Interplanetary Shocks: Van Allen Probes HOPE Observations

    Science.gov (United States)

    Winter, L. M.; Denton, M.; Ferradas, C.; Henderson, M. G.; Larsen, B.; Reeves, G.; Skoug, R. M.; Thomsen, M. F.

    2017-12-01

    The Van Allen Probes' Helium, Oxygen, Proton, and Electron (HOPE) sensors measure ion and electron populations in the plasmasphere, plasma sheet, and lower-energy ring current, providing unique observations at low energies (0.001-50 keV) and low L-shell (down to 1.5 RE). We use the capabilities of these two spacecraft to probe changes in the low energy particles in response to interplanetary (IP) shocks. We focus on changes in the plasma energies, composition, and pitch angle distributions following IP shocks and storm sudden commencements from 2012-2017 through a comparison of HOPE observations preceding and post shock.

  16. The interplanetary shock event of November 11/12 1978, a comprehensive test of acceleration theory

    Science.gov (United States)

    Wenzel, K. P.; Sanderson, T. R.; Vannes, P.; Kennel, C. F.; Scarf, F. L.; Coroniti, F. V.; Russell, C. T.; Parks, G. K.; Smith, E. J.; Feldman, W. C.

    1983-01-01

    A comprehensive study of the November 11/12, 1978 shock event based on energetic particle, solar wind, magnetic field and wave data from the ISEE-3, -1 and -2 spacecraft has been undertaken both from the energetic and the collisionless shock point of view. The energy density of 10-50 keV protons accelerated by the shock is found to be equivalent to the upstream magnetic field energy density. The observations are in quantitative agreement with Lee's (1983) self consistent theory for the excitation of hydromagnetic waves and the acceleration of ions upstream of interplanetary shocks.

  17. The interplanetary shock event of November 11/12 1978 - A comprehensive test of acceleration theory

    Science.gov (United States)

    Wenzel, K.-P.; Sanderson, T. R.; Van Nes, P.; Kennel, C. F.; Scarf, F. L.; Coroniti, F. V.; Russell, C. T.; Parks, G. K.; Smith, E. J.; Feldman, W. C.

    1983-01-01

    A comprehensive study of the November 11, 12, 1978 shock event based on energetic particle, solar wind, magnetic field and wave data from the ISEE-3, -1 and -2 spacecraft has been undertaken both from the energetic and the collisionless shock point of view. The energy density of 10-50 keV protons accelerated by the shock is found to be equivalent to the upstream magnetic field energy density. The observations are in quantitative agreement with Lee's (1983) self consistent theory for the excitation of hydromagnetic waves and the acceleration of ions upstream of interplanetary shocks.

  18. Distributed Interplanetary Delay/Disruption Tolerant Network (DTN) Monitor and Control System

    Science.gov (United States)

    Wang, Shin-Ywan

    2012-01-01

    The main purpose of Distributed interplanetary Delay Tolerant Network Monitor and Control System as a DTN system network management implementation in JPL is defined to provide methods and tools that can monitor the DTN operation status, detect and resolve DTN operation failures in some automated style while either space network or some heterogeneous network is infused with DTN capability. In this paper, "DTN Monitor and Control system in Deep Space Network (DSN)" exemplifies a case how DTN Monitor and Control system can be adapted into a space network as it is DTN enabled.

  19. Navigation Strategy for the Mars 2001 Lander Mission

    Science.gov (United States)

    Mase, Robert A.; Spencer, David A.; Smith, John C.; Braun, Robert D.

    2000-01-01

    control the direction of the lift vector, via bank angle modulation, to keep the vehicle on the desired trajectory. While numerous autonomous guidance algorithms have been developed for use during hypersonic flight at Earth, this will be the first flight of an autonomously directed lifting entry vehicle at Mars. However, without sufficient control and knowledge of the atmospheric entry conditions, the guidance algorithm will not perform effectively. The goal of the interplanetary navigation strategy is to deliver the spacecraft to the desired entry condition with sufficient accuracy and knowledge to enable satisfactory guidance algorithm performance. Specifically, the entry flight path angle must not exceed 0.27 deg. to a 3 sigma confidence level. Entry errors will contribute directly to the size of the landed footprint and the most significant component is entry flight path angle. The size of the entry corridor is limited on the shallow side by integrated heating constraints, and on the steep side by deceleration (g-load) and terminal descent propellant. In order to meet this tight constraint it is necessary to place a targeting maneuver seven hours prior to the time of entry. At this time the trajectory knowledge will be quite accurate, and the effects of maneuver execution errors will be small. The drawback is that entry accuracy is dependent on the success of this final late maneuver. Because propulsive maneuvers are critical events, it is desirable to minimize their occurrence and provide the flight team with as much response time as possible in the event of a spacecraft fault. A mission critical maneuver at Entry - 7 hours does not provide much fault tolerance, and it is desirable to provide a strategy that minimizes reliance on this maneuver. This paper will focus on the Improvements in interplanetary navigation that will decrease entry errors and will reduce the landed footprint, even in the absence of aeromaneuvering. The easiest to take advantage of are

  20. The Navigational Power of Web Browsers

    NARCIS (Netherlands)

    Bielecki, M.; Hidders, J.; Paredaens, J.; Spielmann, M.; Tyszkiewicz, J.; Van den Bussche, J.; http://link.springer.com/article/10.1007/s00224-010-9294-3

    2010-01-01

    We investigate the computational capabilities of Web browsers, when equipped with a standard finite automaton. We observe that Web browsers are Turingcomplete. We introduce the notion of a navigational problem, and investigate the complexity of solving Web queries and navigational problems by Web

  1. The Navigation Metaphor in Security Economics

    DEFF Research Database (Denmark)

    Pieters, Wolter; Barendse, Jeroen; Ford, Margaret

    2016-01-01

    The navigation metaphor for cybersecurity merges security architecture models and security economics. By identifying the most efficient routes for gaining access to assets from an attacker's viewpoint, an organization can optimize its defenses along these routes. The well-understood concept...... of navigation makes it easier to motivate and explain security investment to a wide audience, encouraging strategic security decisions....

  2. Multiple beacons for supporting lunar landing navigation

    Science.gov (United States)

    Theil, Stephan; Bora, Leonardo

    2018-02-01

    The exploration and potential future exploitation of solar system bodies requires technologies for precise and safe landings. Current navigation systems for landing probes are relying on a combination of inertial and optical sensor measurements to determine the current flight state with respect to the target body and the desired landing site. With a future transition from single exploration missions to more frequent first exploration and then exploitation missions, the implementation and operation of these missions changes, since it can be expected that a ground infrastructure on the target body is available in the vicinity of the landing site. In a previous paper, the impact of a single ground-based beacon on the navigation performance was investigated depending on the type of radiometric measurements and on the location of the beacon with respect to the landing site. This paper extends this investigation on options for ground-based multiple beacons supporting the on-board navigation system. It analyzes the impact on the achievable navigation accuracy. For that purpose, the paper introduces briefly the existing navigation architecture based on optical navigation and its extension with radiometric measurements. The same scenario of lunar landing as in the previous paper is simulated. The results are analyzed and discussed. They show a single beacon at a large distance along the landing trajectory and multiple beacons close to the landing site can improve the navigation performance. The results show how large the landing area can be increased where a sufficient navigation performance is achieved using the beacons.

  3. Natural Language Navigation Support in Virtual Reality

    NARCIS (Netherlands)

    van Luin, J.; Nijholt, Antinus; op den Akker, Hendrikus J.A.; Giagourta, V.; Strintzis, M.G.

    2001-01-01

    We describe our work on designing a natural language accessible navigation agent for a virtual reality (VR) environment. The agent is part of an agent framework, which means that it can communicate with other agents. Its navigation task consists of guiding the visitors in the environment and to

  4. Disputing Viking navigation by polarized skylight.

    Science.gov (United States)

    Roslund, C; Beckman, C

    1994-07-20

    The widely held notion that the Vikings utilized polarization of skylight on overcast days for navigational purposes is demonstrated to have no scientific basis. The use of polarized skylight for navigation under partly cloudfree skies should be treated with caution and skepticism.

  5. Autonomous Relative Navigation for Small Spacecraft

    NARCIS (Netherlands)

    Maessen, D.C.

    2014-01-01

    The thesis deals with the relative navigation between two small formation flying spacecraft. The inter-satellite distance is measured using locally generated radiofrequency ranging signals. Design considerations for the spacecraft and the relative navigation system are discussed as well as the

  6. Traffic safety effects of navigation systems

    NARCIS (Netherlands)

    Feenstra, P.J.; Hogema, J.H.; Vonk, T.

    2007-01-01

    Abstract— To investigate effects of navigation systems on traffic safety, a literature search, a damages database analysis, a user survey and an instrumented car study were conducted. This paper presents the instrumented car study to investigate the effects of a navigation system on driving behavior

  7. Vibrotactile in-vehicle navigation system

    NARCIS (Netherlands)

    Erp, J.B.F. van; Veen, H.J. van

    2004-01-01

    A vibrotactile display, consisting ofeight vibrating elements or tactors mounted in a driver's seat, was tested in a driving simulator. Participants drove with visual, tactile and multimodal navigation displays through a built-up area. Workload and the reaction time to navigation messages were

  8. Discovery of Individual User Navigation Styles

    NARCIS (Netherlands)

    Herder, E.; Juvina, I.

    2004-01-01

    Individual differences have been shown to lead to different navigation styles. In this paper we present a pilot study that aims at finding predictors for users’ vulnerability to experience disorientation that can be gathered unobtrusively and in real-time. We identified two navigation styles that we

  9. Rosetta Star Tracker and Navigation Camera

    DEFF Research Database (Denmark)

    Thuesen, Gøsta

    1998-01-01

    Proposal in response to the Invitation to Tender (ITT) issued by Matra Marconi Space (MSS) for the procurement of the ROSETTA Star Tracker and Navigation Camera.......Proposal in response to the Invitation to Tender (ITT) issued by Matra Marconi Space (MSS) for the procurement of the ROSETTA Star Tracker and Navigation Camera....

  10. A Semantic Navigation Model for Video Games

    Science.gov (United States)

    van Driel, Leonard; Bidarra, Rafael

    Navigational performance of artificial intelligence (AI) characters in computer games is gaining an increasingly important role in the perception of their behavior. While recent games successfully solve some complex navigation problems, there is little known or documented on the underlying approaches, often resembling a primitive conglomerate of ad-hoc algorithms for specific situations.

  11. Evolved Navigation Theory and Horizontal Visual Illusions

    Science.gov (United States)

    Jackson, Russell E.; Willey, Chela R.

    2011-01-01

    Environmental perception is prerequisite to most vertebrate behavior and its modern investigation initiated the founding of experimental psychology. Navigation costs may affect environmental perception, such as overestimating distances while encumbered (Solomon, 1949). However, little is known about how this occurs in real-world navigation or how…

  12. Understanding the Social Navigation User Experience

    Science.gov (United States)

    Goecks, Jeremy

    2009-01-01

    A social navigation system collects data from its users--its community--about what they are doing, their opinions, and their decisions, aggregates this data, and provides the aggregated data--community data--back to individuals so that they can use it to guide behavior and decisions. Social navigation systems empower users with the ability to…

  13. Empirically Determined Passenger Ferry Navigable Routes within ...

    African Journals Online (AJOL)

    OLUWASOGO

    modelling of hydrographic information is important to control waterways boat services with existing roadway ... channel accretion. KEYWORDS: Navigable routes, hydrographic information, empirical analysis, under-keel clearance, river bed, topography. [Received May 04 2017; .... on features that may affect safe navigation.

  14. A Comparative Study of Navigation Meshes

    NARCIS (Netherlands)

    van Toll, W.G.; Triesscheijn, Roy; Kallmann, Marcelo; Oliva, Ramon; Pelechano, Nuria; Pettré, Julien; Geraerts, R.J.

    2016-01-01

    A navigation mesh is a representation of a 2D or 3D virtual environment that enables path planning and crowd simulation for walking characters. Various state-of-the-art navigation meshes exist, but there is no standardized way of evaluating or comparing them. Each implementation is in a different

  15. Motion of the sources for type II and type IV radio bursts and flare-associated interplanetary disturbances

    Science.gov (United States)

    Sakurai, K.; Chao, J. K.

    1974-01-01

    Shock waves are indirectly observed as the source of type II radio bursts, whereas magnetic bottles are identified as the source of moving metric type IV radio bursts. The difference between the expansion speeds of these waves and bottles is examined during their generation and propagation near the flare regions. It is shown that, although generated in the explosive phase of flares, the bottles behave quite differently from the waves and that the bottles are generally much slower than the waves. It has been suggested that the waves are related to flare-associated interplanetary disturbances which produce SSC geomagnetic storms. These disturbances may, therefore, be identified as interplanetary shock waves. The relationship among magnetic bottles, shock waves near the sun, and flare-associated disturbances in interplanetary space is briefly discussed.

  16. Ethical Navigation in Leadership Training

    Directory of Open Access Journals (Sweden)

    Øyvind Kvalnes

    2012-05-01

    Full Text Available Business leaders frequently face dilemmas, circumstances where whatever course of action they choose, something of important value will be offended. How can an organisation prepare its decision makers for such situations? This article presents a pedagogical approach to dilemma training for business leaders and managers. It has evolved through ten years of experience with human resource development, where ethics has been an integral part of programs designed to help individuals to become excellent in their professional roles. The core element in our approach is The Navigation Wheel, a figure used to keep track of relevant decision factors. Feedback from participants indicates that dilemma training has helped them to recognise the ethical dimension of leadership. They respond that the tools and concepts are highly relevant in relation to the challenges that occur in the working environment they return to after leadership training.http://dx.doi.org/10.5324/eip.v6i1.1778

  17. A study of solar and interplanetary parameters of CMEs causing major geomagnetic storms during SC 23

    Directory of Open Access Journals (Sweden)

    C. Oprea

    2013-08-01

    Full Text Available In this paper we analyse 25 Earth-directed and strongly geoeffective interplanetary coronal mass ejections (ICMEs which occurred during solar cycle 23, using data provided by instruments on SOHO (Solar and Heliospheric Observatory, ACE (Advanced Composition Explorer and geomagnetic stations. We also examine the in situ parameters, the energy transfer into magnetosphere, and the geomagnetic indexes. We compare observed travel times with those calculated by observed speeds projected into the plane of the sky and de-projected by a simple model. The best fit was found with the projected speeds. No correlation was found between the importance of a flare and the geomagnetic Dst (disturbance storm time index. By comparing the in situ parameters with the Dst index we find a strong connection between some of these parameters (such as Bz, Bs · V and the energy transfer into the magnetosphere with the strength of the geomagnetic storm. No correlation was found with proton density and plasma temperature. A superposed epoch analysis revealed a strong dependence of the Dst index on the southward component of interplanetary magnetic field, Bz, and to the Akasofu coupling function, which evaluates the energy transfer between the ICME and the magnetosphere. The analysis also showed that the geomagnetic field at higher latitudes is disturbed before the field around the Earth's equator.

  18. Design of the VISITOR Tool: A Versatile ImpulSive Interplanetary Trajectory OptimizeR

    Science.gov (United States)

    Corpaccioli, Luca; Linskens, Harry; Komar, David R.

    2014-01-01

    The design of trajectories for interplanetary missions represents one of the most complex and important problems to solve during conceptual space mission design. To facilitate conceptual mission sizing activities, it is essential to obtain sufficiently accurate trajectories in a fast and repeatable manner. To this end, the VISITOR tool was developed. This tool modularly augments a patched conic MGA-1DSM model with a mass model, launch window analysis, and the ability to simulate more realistic arrival and departure operations. This was implemented in MATLAB, exploiting the built-in optimization tools and vector analysis routines. The chosen optimization strategy uses a grid search and pattern search, an iterative variable grid method. A genetic algorithm can be selectively used to improve search space pruning, at the cost of losing the repeatability of the results and increased computation time. The tool was validated against seven flown missions: the average total mission (Delta)V offset from the nominal trajectory was 9.1%, which was reduced to 7.3% when using the genetic algorithm at the cost of an increase in computation time by a factor 5.7. It was found that VISITOR was well-suited for the conceptual design of interplanetary trajectories, while also facilitating future improvements due to its modular structure.

  19. The Acceleration of Thermal Protons and Minor Ions at a Quasi-Parallel Interplanetary Shock

    Science.gov (United States)

    Giacalone, J.; Lario, D.; Lepri, S. T.

    2017-12-01

    We compare the results from self-consistent hybrid simulations (kinetic ions, massless fluid electrons) and spacecraft observations of a strong, quasi-parallel interplanetary shock that crossed the Advanced Composition Explorer (ACE) on DOY 94, 2001. In our simulations, the un-shocked plasma-frame ion distributions are Maxwellian. Our simulations include protons and minor ions (alphas, 3He++, and C5+). The interplanetary shock crossed both the ACE and the Wind spacecraft, and was associated with significant increases in the flux of > 50 keV/nuc ions. Our simulation uses parameters (ion densities, magnetic field strength, Mach number, etc.) consistent with those observed. Acceleration of the ions by the shock, in a manner similar to that expected from diffusive shock acceleration theory, leads to a high-energy tail in the distribution of the post-shock plasma for all ions we considered. The simulated distributions are directly compared to those observed by ACE/SWICS, EPAM, and ULEIS, and Wind/STICS and 3DP, covering the energy range from below the thermal peak to the suprathermal tail. We conclude from our study that the solar wind is the most significant source of the high-energy ions for this event. Our results have important implications for the physics of the so-called `injection problem', which will be discussed.

  20. Source energy spectra from demodulation of solar particle data by interplanetary and coronal transport

    Science.gov (United States)

    Perez-Peraza, J.; Alvarez-Madrigal, M.; Rivero, F.; Miroshnichenko, L. I.

    1985-01-01

    The data on source energy spectra of solar cosmic rays (SCR), i.e. the data on the spectrum form and on the absolute SCR are of interest for three reasons: (1) the SCR contain the energy comparable to the total energy of electromagnetic flare radiation (less than or equal to 10 to the 32nd power ergs); (2) the source spectrum form indicates a possible acceleration mechanism (or mechanism); and (3) the accelerated particles are efficiently involved in nuclear electromagnetic and plasma processes in the solar atmosphere. Therefore, the data on SCR source spectra are necessary for a theoretical description of the processes mentioned and for the formulation of the consistent flare model. Below it is attempted to sound solar particle sources by means of SCR energy spectrum obtained near the Sun, at the level of the roots of the interplanetary field lines in the upper solar corona. Data from approx. 60 solar proton events (SPE) between 1956-1981. These data were obtained mainly by the interplanetary demodulation of observed fluxes near the Earth. Further, a model of coronal azimuthal transport is used to demodulate those spectra, and to obtain the source energy spectra.

  1. Substorms and polar cap convection: the 10 January 2004 interplanetary CME case

    Directory of Open Access Journals (Sweden)

    Y. Andalsvik

    2012-01-01

    Full Text Available The expansion-contraction model of Dungey cell plasma convection has two different convection sources, i.e. reconnections at the magnetopause and in the magnetotail. The spatial-temporal structure of the nightside source is not yet well understood. In this study we shall identify temporal variations in the winter polar cap convection structure during substorm activity under steady interplanetary conditions. Substorm activity (electrojets and particle precipitations is monitored by excellent ground-satellite DMSP F15 conjunctions in the dusk-premidnight sector. We take advantage of the wide latitudinal coverage of the IMAGE chain of ground magnetometers in Svalbard – Scandinavia – Russia for the purpose of monitoring magnetic deflections associated with polar cap convection and substorm electrojets. These are augmented by direct observations of polar cap convection derived from SuperDARN radars and cross-track ion drift observations during traversals of polar cap along the dusk-dawn meridian by spacecraft DMSP F13. The interval we study is characterized by moderate, stable forcing of the magnetosphere-ionosphere system (EKL = 4.0–4.5 mV m−1; cross polar cap potential (CPCP, Φ (Boyle = 115 kV during Earth passage of an interplanetary CME (ICME, choosing an 4-h interval where the magnetic field pointed continuously south-west (Bz By By polarity of the ICME magnetic field, a clear indication of a nightside source.

  2. The structure of plasma-density irregularities in the interplanetary medium

    International Nuclear Information System (INIS)

    Singleton, D.G.

    1975-01-01

    The conflict in the literature as to whether the plasma-density spatial spectrum of the irregularities in the interplanetary medium is of Gaussian or power law form is discussed. Particular attention is paid to the interplanetary scintillation effects ascribed to these irregularities. It is shown that the phase-screen theory of scintillations can be invoked to devise a set of critical tests which provide a means of discriminating between the conflicting hypotheses. Differences in the predicted behaviour of the single sensor temporal spectra of the scintillations for the two irregularity forms provide the main tests of the conflicting hypotheses. However, it is also shown that the two hypotheses lead to different forms of the variation of scintillation index with the observing frequency and the solar elongation of the scintillating source. Consideration is given to the optimum conditions for observing the Fourier and Bessel temporal spectra modulation which is due to the Fresnel filtering of the spatial spectrum. Determination of irregularity shape, orientation and motion in terms of this modulation is also discussed. (author)

  3. HIGH-RESOLUTION IMAGING OF THE GEGENSCHEIN AND THE GEOMETRIC ALBEDO OF INTERPLANETARY DUST

    Energy Technology Data Exchange (ETDEWEB)

    Ishiguro, Masateru; Yang, Hongu [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-742 (Korea, Republic of); Usui, Fumihiko [Department of Space Astronomy and Astrophysics, Institute of Space and Astronautical Science (ISAS), JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Pyo, Jeonghyun [Korea Astronomy and Space Science Institute (KASI), Daejeon 305-348 (Korea, Republic of); Ueno, Munetaka [Institute of Space and Astronautical Science (ISAS), JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Ootsubo, Takafumi [Astronomical Institute, Tohoku University, 6-3 Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Kwon, Suk Minn [Department of Science Education, Kangwon National University, 192-1 Hyoja-dong, Kangwon-do, Chunchon 200-701 (Korea, Republic of); Mukai, Tadashi, E-mail: ishiguro@astro.snu.ac.kr [Department of Earth and Planetary Sciences, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501 (Japan)

    2013-04-10

    We performed optical observations of the Gegenschein using a liquid-nitrogen-cooled wide-field camera, the Wide-field Imager of Zodiacal light with ARray Detector (WIZARD), between 2003 March and 2006 November. We found a narrow brightness enhancement superimposed on the smooth gradient of the Gegenschein at the exact position of the antisolar point. Whereas the Gegenschein morphology changed according to the orbital motion of the Earth, the maximum brightness coincided with the antisolar direction throughout the year. We compared the observed morphology of the Gegenschein with those of models in which the spatial density of the interplanetary dust cloud was considered and found that the volume scattering phase function had a narrow backscattering enhancement. The morphology was reproducible with a spatial distribution model for infrared zodiacal emission. It is likely that the zero-phase peak (the so-called opposition effect) was caused by coherent backscattering and/or shadow-hiding effects on the rough surfaces of individual dust particles. These results suggest that big particles are responsible for both zodiacal light and zodiacal emission. Finally, we derived the geometric albedo of the smooth component of interplanetary dust, assuming big particles, and obtained a geometric albedo of 0.06 {+-} 0.01. The derived albedo is in accordance with collected dark micrometeorites and observed cometary dust particles. We concluded that chondritic particles are dominant near Earth space, supporting the recent theoretical study by dynamical simulation.

  4. Fundamental issues on kappa-distributions in space plasmas and interplanetary proton distributions

    International Nuclear Information System (INIS)

    Leubner, M.P.

    2004-01-01

    Numerous in situ observations indicate clearly the presence of nonthermal electron and ion structures as ubiquitous and persistent feature in a variety of astrophysical plasma environments. In particular, the detected suprathermal particle populations are accurately represented by the family of κ-distributions, a power-law in particle speed. After clarifying the characteristics of high-energy tail distributions under various space plasma conditions, different generation mechanisms of energetic particles are introduced where numerical simulations of wave-particle interaction based on a Fokker-Planck approach demonstrate how Landau interaction ultimately leads to κ-like distributions. Because of lack of theoretical justification, the use of the analytical form of κ-functions was frequently criticized. It is shown that these distributions turn out as consequence of an entropy generalization favored by nonextensive thermo-statistics, thus providing the missing link for powerlaw models of suprathermal tails from fundamental physics, along with a physical interpretation of the structure parameter κ. Moreover, with regard to the full nonextensive formalism, compatible also with negative values of κ, it is demonstrated that core-halo distribution structures, as observed for instance under typical interplanetary plasma conditions, are a natural content of the pseudo-additive entropy concept. The significance of the complete κ-distribution family with regard to observed core-halo electron and double-humped ion velocity space characteristics is illuminated, where the observed peak separation scale of interplanetary proton distributions is compatible with a maximum entropy condition

  5. Sunward-propagating Solar Energetic Electrons inside Multiple Interplanetary Flux Ropes

    Energy Technology Data Exchange (ETDEWEB)

    Gómez-Herrero, Raúl; Hidalgo, Miguel A.; Carcaboso, Fernando; Blanco, Juan J. [Dpto. de Física y Matemáticas, Universidad de Alcalá, E-28871 Alcalá de Henares, Madrid (Spain); Dresing, Nina; Klassen, Andreas; Heber, Bernd [Institut für Experimentelle und Angewandte Physik, University of Kiel, D-24118, Kiel (Germany); Temmer, Manuela; Veronig, Astrid [Institute of Physics/Kanzelhöhe Observatory, University of Graz, A-8010 Graz (Austria); Bučík, Radoslav [Institut für Astrophysik, Georg-August-Universität Göttingen, D-37077, Göttingen (Germany); Lario, David, E-mail: raul.gomezh@uah.es [The Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723 (United States)

    2017-05-10

    On 2013 December 2 and 3, the SEPT and STE instruments on board STEREO-A observed two solar energetic electron events with unusual sunward-directed fluxes. Both events occurred during a time interval showing typical signatures of interplanetary coronal mass ejections (ICMEs). The electron timing and anisotropies, combined with extreme-ultraviolet solar imaging and radio wave spectral observations, are used to confirm the solar origin and the injection times of the energetic electrons. The solar source of the ICME is investigated using remote-sensing observations and a three-dimensional reconstruction technique. In situ plasma and magnetic field data combined with energetic electron observations and a flux-rope model are used to determine the ICME magnetic topology and the interplanetary electron propagation path from the Sun to 1 au. Two consecutive flux ropes crossed the STEREO-A location and each electron event occurred inside a different flux rope. In both cases, the electrons traveled from the solar source to 1 au along the longest legs of the flux ropes still connected to the Sun. During the December 2 event, energetic electrons propagated along the magnetic field, while during the December 3 event they were propagating against the field. As found by previous studies, the energetic electron propagation times are consistent with a low number of field line rotations N < 5 of the flux rope between the Sun and 1 au. The flux rope model used in this work suggests an even lower number of rotations.

  6. Effective Acceleration Model for the Arrival Time of Interplanetary Shocks driven by Coronal Mass Ejections

    Science.gov (United States)

    Paouris, Evangelos; Mavromichalaki, Helen

    2017-12-01

    In a previous work (Paouris and Mavromichalaki in Solar Phys. 292, 30, 2017), we presented a total of 266 interplanetary coronal mass ejections (ICMEs) with as much information as possible. We developed a new empirical model for estimating the acceleration of these events in the interplanetary medium from this analysis. In this work, we present a new approach on the effective acceleration model (EAM) for predicting the arrival time of the shock that preceds a CME, using data of a total of 214 ICMEs. For the first time, the projection effects of the linear speed of CMEs are taken into account in this empirical model, which significantly improves the prediction of the arrival time of the shock. In particular, the mean value of the time difference between the observed time of the shock and the predicted time was equal to +3.03 hours with a mean absolute error (MAE) of 18.58 hours and a root mean squared error (RMSE) of 22.47 hours. After the improvement of this model, the mean value of the time difference is decreased to -0.28 hours with an MAE of 17.65 hours and an RMSE of 21.55 hours. This improved version was applied to a set of three recent Earth-directed CMEs reported in May, June, and July of 2017, and we compare our results with the values predicted by other related models.

  7. ACE EPAM and Van Allen Probes RBSPICE measurements of interplanetary oxygen injection to the inner magnetosphere

    Science.gov (United States)

    Patterson, J. D.; Manweiler, J. W.; Gerrard, A. J.; Lanzerotti, L. J.

    2015-12-01

    On March 17, 2015, a significant oxygen-rich interplanetary event was measure by the Advanced Composition Explorer (ACE) Electron Proton Alpha Monitor (EPAM) instrument. At the same time the Van Allen Probes Radiation Belt Storm Probes Ion Composition Experiment (RBSPICE) instrument recorded significant enhancements of oxygen in the inner magnetosphere. We present a detailed analysis of this event utilizing a new method of exploiting the EPAM Pulse Height Analyzer (PHA) data to precisely resolve helium and oxygen spectra within the 0.5 to 5 MeV/nuc range. We also present the flux, partial particle pressures, and pitch angle distributions of the ion measurements from RBSPICE. During this event, both EPAM and RBSPICE measured O:He ratios greater than 10:1. The pitch angle distributions from RBSPICE-B show a strong beam of oxygen at an L ~ 5.8 early on March 17th during orbit. The timing between the observations of the oxygen peak at ACE and the beam observed at RBSPICE-B is consistent with the travel-time required for energetic particle transport from L1 to Earth and access to the magnetosphere. We assert that the oxygen seen by RBSPICE during the initial phase of this event is the result of direct injection from the interplanetary medium of energetic ions. This poster contains the observations and detailed calculations to support this assertion.

  8. Interplanetary and terrestrial observations of an Earth-directed coronal mass ejection

    Science.gov (United States)

    Vats, Hari Om; Sharma, Som; Oza, R.; Iyer, K. N.; Chandra, H.; Sawant, H. S.; Deshpande, M. R.

    2001-01-01

    In this article we report interplanetary scintillation observations at 103 and 327 MHz of an Earth-directed coronal mass ejection (CME) which occurred near the center of the solar disk at 0435 UT on May 12, 1997. The disturbance was found to have plasma density ˜4 times more than that of the ambient plasma at a distance of ˜ 0.5 AU from the Sun. The most peculiar aspect of this CME is that it appears that the disturbance moved slightly slower than the ambient medium. Solar and Heliospheric Observatory (SOHO) and interplanetary scintillation (IPS) estimates of solar wind are quite different; it appears that the difference could be due to the projection effect of the SOHO image.Though the disturbance was not very severe, its impact on Earth's environment produced a geomagnetic storm. This event was associated with a two-ribbon flare.The ionospheric effects of soft X rays from this solar flare were observed by a digital ionosonde at Ahmedabad in the form of excess ionization (˜1200 el cm-3) in the D region of the ionosphere.

  9. Interaction of the interplanetary shock and tangential discontinuity in the solar wind

    Science.gov (United States)

    Goncharov, Oleksandr; Koval, Andriy; Safrankova, Jana; Nemecek, Zdenek; Prech, Lubomir; Szabo, Adam; Zastenker, Georgy N.

    2017-04-01

    Collisionless shocks play a significant role in the solar wind interaction with the Earth. Fast forward interplanetary (IP) shocks driven by coronal mass ejections or by interaction of fast and slow solar wind streams can be encountered in the interplanetary space, while the bow shock is a standing fast reverse shock formed by the interaction of the supersonic solar wind with Earth's magnetic field. Both types of shocks are responsible for a transformation of a part of the energy of the directed solar wind motion to plasma heating and to acceleration of reflected particles to high energies. It is well known that the interaction of tangential discontinuities with the bow shock can create hot flow anomalies but interactions between IP shocks and tangential discontinuities in the solar wind are studied to a lesser extent due to lack of observations. A fortunate position of many spacecraft (Wind, ACE, DSCOVR, THEMIS, Spektr-R) on June 22, 2015 allows us detailed observations of an IP shock modification due to this interaction. We present an analysis of the event supported with MHD modeling that reveals basic features of the observed IP shock ramp splitting. However, a good matching of modeling and observations was found for DSCOVR and Spektr-R located above the ecliptic plane, whereas a timing of observations below this plane demonstrates problems of modeling of highly inclined discontinuities.

  10. Variation of Solar, Interplanetary and Geomagnetic Parameters during Solar Cycles 21-24

    Directory of Open Access Journals (Sweden)

    Suyeon Oh

    2013-06-01

    Full Text Available The length of solar cycle 23 has been prolonged up to about 13 years. Many studies have speculated that the solar cycle 23/24 minimum will indicate the onset of a grand minimum of solar activity, such as the Maunder Minimum. We check the trends of solar (sunspot number, solar magnetic fields, total solar irradiance, solar radio flux, and frequency of solar X-ray flare, interplanetary (interplanetary magnetic field, solar wind and galactic cosmic ray intensity, and geomagnetic (Ap index parameters (SIG parameters during solar cycles 21-24. Most SIG parameters during the period of the solar cycle 23/24 minimum have remarkably low values. Since the 1970s, the space environment has been monitored by ground observatories and satellites. Such prevalently low values of SIG parameters have never been seen. We suggest that these unprecedented conditions of SIG parameters originate from the weakened solar magnetic fields. Meanwhile, the deep 23/24 solar cycle minimum might be the portent of a grand minimum in which the global mean temperature of the lower atmosphere is as low as in the period of Dalton or Maunder minimum.

  11. Scaling exponents of the velocity structure functions in the interplanetary medium

    Directory of Open Access Journals (Sweden)

    V. Carbone

    Full Text Available We analyze the scaling exponents of the velocity structure functions, obtained from the velocity fluctuations measured in the interplanetary space plasma. Using the expression for the energy transfer rate which seems the most relevant in describing the evolution of the pseudo-energy densities in the interplanetary medium, we introduce an energy cascade model derived from a simple fragmentation process, which takes into account the intermittency effect. In the absence and in the presence of the large-scale magnetic field decorrelation effect the model reduces to the fluid and the hydromagnetic p-model, respectively. We show that the scaling exponents of the q-th power of the velocity structure functions, as obtained by the model in the absence of the decorrelation effect, furnishes the best-fit to the data analyzed from the Voyager 2 velocity field measurements at 8.5 AU. Our results allow us to hypothesize a new kind of scale-similarity for magnetohydrodynamic turbulence when the decorrelation effect is at work, related to the fourth-order velocity structure function.

  12. An interplanetary shock traced by planetary auroral storms from the Sun to Saturn.

    Science.gov (United States)

    Prangé, Renée; Pallier, Laurent; Hansen, Kenneth C; Howard, Russ; Vourlidas, Angelos; Courtin, Régis; Parkinson, Chris

    2004-11-04

    A relationship between solar activity and aurorae on Earth was postulated long before space probes directly detected plasma propagating outwards from the Sun. Violent solar eruption events trigger interplanetary shocks that compress Earth's magnetosphere, leading to increased energetic particle precipitation into the ionosphere and subsequent auroral storms. Monitoring shocks is now part of the 'Space Weather' forecast programme aimed at predicting solar-activity-related environmental hazards. The outer planets also experience aurorae, and here we report the discovery of a strong transient polar emission on Saturn, tentatively attributed to the passage of an interplanetary shock--and ultimately to a series of solar coronal mass ejection (CME) events. We could trace the shock-triggered events from Earth, where auroral storms were recorded, to Jupiter, where the auroral activity was strongly enhanced, and to Saturn, where it activated the unusual polar source. This establishes that shocks retain their properties and their ability to trigger planetary auroral activity throughout the Solar System. Our results also reveal differences in the planetary auroral responses on the passing shock, especially in their latitudinal and local time dependences.

  13. SLS Model Based Design: A Navigation Perspective

    Science.gov (United States)

    Oliver, T. Emerson; Anzalone, Evan; Park, Thomas; Geohagan, Kevin

    2018-01-01

    The SLS Program has implemented a Model-based Design (MBD) and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team is responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1B design, the additional GPS Receiver hardware model is managed as a DMM at the vehicle design level. This paper describes the models, and discusses the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the navigation components.

  14. Gamifying Navigation in Location-Based Applications

    DEFF Research Database (Denmark)

    Nadarajah, Stephanie Githa; Overgaard, Benjamin Nicholas; Pedersen, Peder Walz

    2017-01-01

    Location-based games entertain players usually by interactions at points of interest (POIs). Navigation between POIs often involve the use of either a physical or digital map, not taking advantage of the opportunity available to engage users in activities between POIs. The paper presents riddle...... solving as a navigational method for a location-based game. 10 families with 2-6 persons and at least one child in the age range 9-11 years old participated in the evaluation. Results show that riddle solving as a navigational method is more enjoyable than a 2D digital map. Additional findings from video...

  15. Navsat - A global satellite based navigation system

    Science.gov (United States)

    Rosetti, C.; Carnebianca, C.

    The Navsat 12-satellite highly eccentric orbit - plus - six-satellite geosynchronous orbit system constellation currently accepted as the baseline design is noted to be able to significantly reduce operating costs while furnishing navigation performance comparable or superior to that of GPS. The constellation is also noted to facilitate the implementation of the planned integrated navigation/communications/search-and-rescue service. With only two geosynchronous navigation satellites and three highly eccentric orbit satellites, full operational capability is achievable in the areas where the service is most needed.

  16. Computer assisted navigation in knee arthroplasty.

    Science.gov (United States)

    Bae, Dae Kyung; Song, Sang Jun

    2011-12-01

    Computer assisted surgery (CAS) was used to improve the positioning of implants during total knee arthroplasty (TKA). Most studies have reported that computer assisted navigation reduced the outliers of alignment and component malpositioning. However, additional sophisticated studies are necessary to determine if the improvement of alignment will improve long-term clinical results and increase the survival rate of the implant. Knowledge of CAS-TKA technology and understanding the advantages and limitations of navigation are crucial to the successful application of the CAS technique in TKA. In this article, we review the components of navigation, classification of the system, surgical method, potential error, clinical results, advantages, and disadvantages.

  17. Navigating nuclear science: Enhancing analysis through visualization

    Energy Technology Data Exchange (ETDEWEB)

    Irwin, N.H.; Berkel, J. van; Johnson, D.K.; Wylie, B.N.

    1997-09-01

    Data visualization is an emerging technology with high potential for addressing the information overload problem. This project extends the data visualization work of the Navigating Science project by coupling it with more traditional information retrieval methods. A citation-derived landscape was augmented with documents using a text-based similarity measure to show viability of extension into datasets where citation lists do not exist. Landscapes, showing hills where clusters of similar documents occur, can be navigated, manipulated and queried in this environment. The capabilities of this tool provide users with an intuitive explore-by-navigation method not currently available in today`s retrieval systems.

  18. Enhancing Navigation Skills through Audio Gaming.

    Science.gov (United States)

    Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

    2010-01-01

    We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks.

  19. Enhancing Navigation Skills through Audio Gaming

    Science.gov (United States)

    Sánchez, Jaime; Sáenz, Mauricio; Pascual-Leone, Alvaro; Merabet, Lotfi

    2014-01-01

    We present the design, development and initial cognitive evaluation of an Audio-based Environment Simulator (AbES). This software allows a blind user to navigate through a virtual representation of a real space for the purposes of training orientation and mobility skills. Our findings indicate that users feel satisfied and self-confident when interacting with the audio-based interface, and the embedded sounds allow them to correctly orient themselves and navigate within the virtual world. Furthermore, users are able to transfer spatial information acquired through virtual interactions into real world navigation and problem solving tasks. PMID:25505796

  20. INTERACTION SPECIFICITY IN AIR NAVIGATION COMMUNICATION

    Directory of Open Access Journals (Sweden)

    Kateryna Povoroznyk

    2012-09-01

    Full Text Available  The article is about a problem of air navigation communication and the positive influence of interpersonal communication for air navigation specialists. The ability of organizing a dialogue with subject – subject relationship substantially increase professional interaction efficiency. As scientific surveys show a dialogue is not just the form of communication, but an organizing phenomenon that directly influences the quality of air navigation communication, but there is still a gap in the aviation English teaching technics, mainly due to lack of psycho – pedagogical knowledge concerning human factor peculiarities within dialogical relationship framework. The article highlights the possible ways of the problem solution.

  1. Qatari Women Navigating Gendered Space

    Directory of Open Access Journals (Sweden)

    Krystyna Golkowska

    2017-10-01

    Full Text Available ADespite growing interest in the lived experience of Muslim women in Arab countries, there is still a dearth of studies on the Gulf region. This article focuses on Qatar, a Gulf Corporation Council (GCC country, to explore its changing sociocultural landscape and reflect on Qatari women’s agency within the framework of the traditional gendered space model. Applying Grounded Theory methodology to data collected from a variety of scholarly and non-scholarly sources, the author offers a themed overview of factors that facilitate and constrain Qatari women’s mobility. The findings testify to a significant increase in female presence and visibility in the public sphere—specifically in the spaces of education, employment, and sports. They also show that young Qatari women exercise agency through navigating the existing systems rather than question traditional socio-cultural norms. The paper identifies this search for a middle ground between tradition and modernity and its ideological underpinnings as the area of future research that should be led by Qatari women themselves.

  2. Dynamical modeling approach to risk assessment for radiogenic leukemia among astronauts engaged in interplanetary space missions.

    Science.gov (United States)

    Smirnova, Olga A; Cucinotta, Francis A

    2018-02-01

    A recently developed biologically motivated dynamical model of the assessment of the excess relative risk (ERR) for radiogenic leukemia among acutely/continuously irradiated humans (Smirnova, 2015, 2017) is applied to estimate the ERR for radiogenic leukemia among astronauts engaged in long-term interplanetary space missions. Numerous scenarios of space radiation exposure during space missions are used in the modeling studies. The dependence of the ERR for leukemia among astronauts on several mission parameters including the dose equivalent rates of galactic cosmic rays (GCR) and large solar particle events (SPEs), the number of large SPEs, the time interval between SPEs, mission duration, the degree of astronaut's additional shielding during SPEs, the degree of their additional 12-hour's daily shielding, as well as the total mission dose equivalent, is examined. The results of the estimation of ERR for radiogenic leukemia among astronauts, which are obtained in the framework of the developed dynamical model for various scenarios of space radiation exposure, are compared with the corresponding results, computed by the commonly used linear model. It is revealed that the developed dynamical model along with the linear model can be applied to estimate ERR for radiogenic leukemia among astronauts engaged in long-term interplanetary space missions in the range of applicability of the latter. In turn, the developed dynamical model is capable of predicting the ERR for leukemia among astronauts for the irradiation regimes beyond the applicability range of the linear model in emergency cases. As a supplement to the estimations of cancer incidence and death (REIC and REID) (Cucinotta et al., 2013, 2017), the developed dynamical model for the assessment of the ERR for leukemia can be employed on the pre-mission design phase for, e.g., the optimization of the regimes of astronaut's additional shielding in the course of interplanetary space missions. The developed model can

  3. A DATABASE OF >20 keV ELECTRON GREEN'S FUNCTIONS OF INTERPLANETARY TRANSPORT AT 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Agueda, N.; Sanahuja, B. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos, Universitat de Barcelona, Barcelona (Spain); Vainio, R. [Department of Physics, University of Helsinki, Helsinki (Finland)

    2012-10-15

    We use interplanetary transport simulations to compute a database of electron Green's functions, i.e., differential intensities resulting at the spacecraft position from an impulsive injection of energetic (>20 keV) electrons close to the Sun, for a large number of values of two standard interplanetary transport parameters: the scattering mean free path and the solar wind speed. The nominal energy channels of the ACE, STEREO, and Wind spacecraft have been used in the interplanetary transport simulations to conceive a unique tool for the study of near-relativistic electron events observed at 1 AU. In this paper, we quantify the characteristic times of the Green's functions (onset and peak time, rise and decay phase duration) as a function of the interplanetary transport conditions. We use the database to calculate the FWHM of the pitch-angle distributions at different times of the event and under different scattering conditions. This allows us to provide a first quantitative result that can be compared with observations, and to assess the validity of the frequently used term beam-like pitch-angle distribution.

  4. Navigation with a passive brain based interface

    NARCIS (Netherlands)

    Erp, J.B.F. van; Werkhoven, P.J.; Thurlings, M.E.; Brouwer, A.-M.

    2009-01-01

    In this paper, we describe a Brain Computer Interface (BCI) for navigation. The system is based on detecting brain signals that are elicited by tactile stimulation on the torso indicating the desired direction.

  5. Helicopter Urban Navigation Training Using Virtual Environments

    National Research Council Canada - National Science Library

    Wright, George

    2000-01-01

    .... Navigation is a means to an end. Helicopter operations, being inherently expensive and unforgiving of mistakes, are prime candidates for such innovative training techniques as virtual (3-D) fly-throughs...

  6. Plenoptic Imager for Automated Surface Navigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Autonomous and semi-autonomous robotic systems require information about their surroundings in order to navigate properly. A video camera machine vision system can...

  7. Angles-Only Navigation System for Nanosatellites

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the proposed work is to develop and implement an angles-only relative navigation system on hardware suitable for deployment on nanosatellites or...

  8. Comprehension and navigation of networked hypertexts

    NARCIS (Netherlands)

    Blom, Helen; Segers, Eliane; Knoors, Harry; Hermans, Daan; Verhoeven, Ludo

    2018-01-01

    This study aims to investigate secondary school students' reading comprehension and navigation of networked hypertexts with and without a graphic overview compared to linear digital texts. Additionally, it was studied whether prior knowledge, vocabulary, verbal, and visual working memory moderated

  9. Radio Navigation Waveform Experiment, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA is installing the Communications, Navigation, and Networking reConfigurable Testbed (CoNNeCT) onto the truss of the International Space Station to demonstrate...

  10. Onboard Optical Navigation Measurement Processing in GEONS

    Data.gov (United States)

    National Aeronautics and Space Administration — Optical Navigation (OpNav) measurements derived from spacecraft-based images are a powerful data type in the precision orbit determination process.  OpNav...

  11. Fuzzy Logic Controller for Small Satellites Navigation

    National Research Council Canada - National Science Library

    Della Pietra, G; Falzini, S; Colzi, E; Crisconio, M

    2005-01-01

    .... The navigator aims at operating satellites in orbit with a minimum ground support and very good performances, by the adoption of innovative technologies, such as attitude observation GPS, attitude...

  12. NOAA Seamless Raster Navigational Charts (RNC)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Seamless Raster Chart Server provides a seamless collarless mosaic of the NOAA Raster Navigational Charts (RNC). The RNC are a collection of approximately...

  13. 5th China Satellite Navigation Conference

    CERN Document Server

    Jiao, Wenhai; Wu, Haitao; Lu, Mingquan

    2014-01-01

    China Satellite Navigation Conference (CSNC) 2014 Proceedings presents selected research papers from CSNC2014, held on 21-23 May in Nanjing, China. The theme of CSNC2014 is 'BDS Application: Innovation, Integration and Sharing'. These papers discuss the technologies and applications of the Global Navigation Satellite System (GNSS), and the latest progress made in the China BeiDou System (BDS) especially. They are divided into 9 topics to match the corresponding sessions in CSNC2014, which broadly covered key topics in GNSS. Readers can learn about the BDS and keep abreast of the latest advances in GNSS techniques and applications.  SUN Jiadong is the Chief Designer of the Compass/ BDS, and the Academician of Chinese Academy of Sciences (CAS); JIAO Wenhai is a researcher at China Satellite Navigation Office; WU Haitao is a professor at Navigation Headquarters, CAS; LU Mingquan is a professor at Department of Electronic Engineering of Tsinghua University.

  14. Inertial Navigation System Aiding Using Vision

    Science.gov (United States)

    2013-03-01

    24 Aa Continuos -Time Dynamics Matrix . . . . . . . . . . . . . . . . . . . . . . . . 25 ∆T Sampling Interval...simultaneously tracked. Complete INS aiding action means all of the navigation states receive some improvement from the measurement when compared to the...the y direction. There also are improvements in the other seven navigation states estimates, as shown in Figures A.2 through A.5. In Figures A.4 and A

  15. Neurobiologically inspired mobile robot navigation and planning

    Directory of Open Access Journals (Sweden)

    Mathias Quoy

    2007-11-01

    Full Text Available After a short review of biologically inspired navigation architectures, mainly relying on modeling the hippocampal anatomy, or at least some of its functions, we present a navigation and planning model for mobile robots. This architecture is based on a model of the hippocampal and prefrontal interactions. In particular, the system relies on the definition of a new cell type “transition cells” that encompasses traditional “place cells”.

  16. Mobile Navigation for Sport’s Pilots

    OpenAIRE

    Dušan Fister; Janez Kramberger; Jani Dugonik

    2013-01-01

    Today, global object-positioning is accomplished very precisely by GPS satellite technology. Access to this information is provided globally by widespread mobile devices with integrated GPS receivers from everywhere also from airplane. This paper presents a mobile device using GPS receiver to be used by mobile navigation for sports pilots. In fact, the mobile navigation is a mobile application running on Android. Thus, the current position of the airplane is indicated on the GoogleMaps and co...

  17. Interferometric inversion for passive imaging and navigation

    Science.gov (United States)

    2017-05-01

    digital TV or cellular communication signals in order to perform 1) source geolocation from a moving platform, and conversely 2) navigation of the moving...navigation. First, we analyze the potential of using commercial digital TV or cellular communication signals in order to perform 1) source geolocation from...applica- tions among others in adversarial channel estimation when the incident pulse is unknown. In this reporting period, we considered the situation of

  18. Shape Perception and Navigation in Blind Adults.

    Science.gov (United States)

    Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

    2017-01-01

    Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of these compensatory mechanisms are not completely clear. Both enhanced and impaired reliance on auditory cues in blind individuals have been reported. Here, we develop a new paradigm to test both auditory perception and navigation skills in blind and sighted individuals and to investigate the effect that visual experience has on the ability to reproduce simple and complex paths. During the navigation task, early blind, late blind and sighted individuals were required first to listen to an audio shape and then to recognize and reproduce it by walking. After each audio shape was presented, a static sound was played and the participants were asked to reach it. Movements were recorded with a motion tracking system. Our results show three main impairments specific to early blind individuals. The first is the tendency to compress the shapes reproduced during navigation. The second is the difficulty to recognize complex audio stimuli, and finally, the third is the difficulty in reproducing the desired shape: early blind participants occasionally reported perceiving a square but they actually reproduced a circle during the navigation task. We discuss these results in terms of compromised spatial reference frames due to lack of visual input during the early period of development.

  19. Navigation domain representation for interactive multiview imaging.

    Science.gov (United States)

    Maugey, Thomas; Daribo, Ismael; Cheung, Gene; Frossard, Pascal

    2013-09-01

    Enabling users to interactively navigate through different viewpoints of a static scene is a new interesting functionality in 3D streaming systems. While it opens exciting perspectives toward rich multimedia applications, it requires the design of novel representations and coding techniques to solve the new challenges imposed by the interactive navigation. In particular, the encoder must prepare a priori a compressed media stream that is flexible enough to enable the free selection of multiview navigation paths by different streaming media clients. Interactivity clearly brings new design constraints: the encoder is unaware of the exact decoding process, while the decoder has to reconstruct information from incomplete subsets of data since the server generally cannot transmit images for all possible viewpoints due to resource constrains. In this paper, we propose a novel multiview data representation that permits us to satisfy bandwidth and storage constraints in an interactive multiview streaming system. In particular, we partition the multiview navigation domain into segments, each of which is described by a reference image (color and depth data) and some auxiliary information. The auxiliary information enables the client to recreate any viewpoint in the navigation segment via view synthesis. The decoder is then able to navigate freely in the segment without further data request to the server; it requests additional data only when it moves to a different segment. We discuss the benefits of this novel representation in interactive navigation systems and further propose a method to optimize the partitioning of the navigation domain into independent segments, under bandwidth and storage constraints. Experimental results confirm the potential of the proposed representation; namely, our system leads to similar compression performance as classical inter-view coding, while it provides the high level of flexibility that is required for interactive streaming. Because of

  20. Shape Perception and Navigation in Blind Adults

    Science.gov (United States)

    Gori, Monica; Cappagli, Giulia; Baud-Bovy, Gabriel; Finocchietti, Sara

    2017-01-01

    Different sensory systems interact to generate a representation of space and to navigate. Vision plays a critical role in the representation of space development. During navigation, vision is integrated with auditory and mobility cues. In blind individuals, visual experience is not available and navigation therefore lacks this important sensory signal. In blind individuals, compensatory mechanisms can be adopted to improve spatial and navigation skills. On the other hand, the limitations of these compensatory mechanisms are not completely clear. Both enhanced and impaired reliance on auditory cues in blind individuals have been reported. Here, we develop a new paradigm to test both auditory perception and navigation skills in blind and sighted individuals and to investigate the effect that visual experience has on the ability to reproduce simple and complex paths. During the navigation task, early blind, late blind and sighted individuals were required first to listen to an audio shape and then to recognize and reproduce it by walking. After each audio shape was presented, a static sound was played and the participants were asked to reach it. Movements were recorded with a motion tracking system. Our results show three main impairments specific to early blind individuals. The first is the tendency to compress the shapes reproduced during navigation. The second is the difficulty to recognize complex audio stimuli, and finally, the third is the difficulty in reproducing the desired shape: early blind participants occasionally reported perceiving a square but they actually reproduced a circle during the navigation task. We discuss these results in terms of compromised spatial reference frames due to lack of visual input during the early period of development. PMID:28144226

  1. Navigational Strategies of Migrating Monarch Butterflies

    Science.gov (United States)

    2014-11-10

    AFRL-OSR-VA-TR-2014-0339 NAVIGATIONAL STRATEGIES OF MIGRATING MONARCH BUTTERFLIES Steven Reppert UNIVERSITY OF MASSACHUSETTS Final Report 11/10/2014...Final Progress Statement to (Dr. Patrick Bradshaw) Contract/Grant Title: Navigational Strategies of Migrating Monarch Butterflies Contract...Grant #: FA9550-10-1-0480 Reporting Period: 01-Sept-10 to 31-Aug-14 Overview of accomplishments: Migrating monarch butterflies (Danaus

  2. 75 FR 39632 - Regulated Navigation Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey...

    Science.gov (United States)

    2010-07-12

    ..., Algiers Canal, New Orleans, LA; Correction ACTION: Interim rule; Correction. SUMMARY: In the Federal... Area; Gulf Intracoastal Waterway, Inner Harbor Navigation Canal, Harvey Canal, Algiers Canal, New...

  3. Effects of Visual, Auditory, and Tactile Navigation Cues on Navigation Performance, Situation Awareness, and Mental Workload

    National Research Council Canada - National Science Library

    Davis, Bradley M

    2007-01-01

    .... Results from both experiments indicate that augmented visual displays reduced time to complete navigation, maintained situation awareness, and drastically reduced mental workload in comparison...

  4. 33 CFR 207.800 - Collection of navigation statistics.

    Science.gov (United States)

    2010-07-01

    ... statistics. 207.800 Section 207.800 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.800 Collection of navigation statistics. (a... received by the Waterborne Commerce Statistics Center within 30 days after the close of the month in which...

  5. Navigation in medical Internet image databases.

    Science.gov (United States)

    Frankewitsch, T; Prokosch, U

    2001-01-01

    The world wide web (WWW) changes common ideas of database access. Hypertext Markup Language allows the simultaneous presentation of information from different sources such as static pages, results of queries from) databases or dynamically generated pages. 'Therefore, the metaphor of the WWW itself as a database was proposed by Mendelzon and Nlilo in 1998. Against this background the techniques of navigation within WWW-databases and the semantic types of their queries has e been analysed. Forty eight image repositories of different types and content, but all concerning medical essence, have been found by search-engines. Many different techniques are offered to enable navigation ranging from simple HTML-link-lists to complex applets. The applets in particular promise an improvement for navigation. Within the meta-information for querying, only ACR- and UMLS-encoding were found, but not standardized vocabularies like ICD10 or Terminologia Anatomica. UMLS especially shows that a well defined thesaurus can improve navigation. However, of the analysed databases only the UMLS 'metathesaurus' is currently implemented without providing additional navigation support based on the UMLS 'semantic network'. Including the information about relationships between the concepts of the metathesaurus or using the UMLS semantic network could provide a much easier navigation within a network of concepts pointing to multimedia files stored somewhere in the WWW.

  6. Navigability of temporal networks in hyperbolic space.

    Science.gov (United States)

    Ortiz, Elisenda; Starnini, Michele; Serrano, M Ángeles

    2017-11-08

    Information routing is one of the main tasks in many complex networks with a communication function. Maps produced by embedding the networks in hyperbolic space can assist this task enabling the implementation of efficient navigation strategies. However, only static maps have been considered so far, while navigation in more realistic situations, where the network structure may vary in time, remains largely unexplored. Here, we analyze the navigability of real networks by using greedy routing in hyperbolic space, where the nodes are subject to a stochastic activation-inactivation dynamics. We find that such dynamics enhances navigability with respect to the static case. Interestingly, there exists an optimal intermediate activation value, which ensures the best trade-off between the increase in the number of successful paths and a limited growth of their length. Contrary to expectations, the enhanced navigability is robust even when the most connected nodes inactivate with very high probability. Finally, our results indicate that some real networks are ultranavigable and remain highly navigable even if the network structure is extremely unsteady. These findings have important implications for the design and evaluation of efficient routing protocols that account for the temporal nature of real complex networks.

  7. Coordinates Analyses of Hydrated Interplanetary Dust Particles: Samples of Primitive Solar System Bodies

    Science.gov (United States)

    Keller, L. P.; Snead, C.; McKeegan, K. D.

    2016-01-01

    Interplanetary dust particles (IDPs) collected in the stratosphere fall into two major groups: an anhydrous group termed the "chondritic-porous (CP) IDPs and a hydrated group, the "chondritic-smooth (CS) IDPs, although rare IDPs with mineralogies intermediate between these two groups are known [1]. The CP-IDPs are widely believed to be derived from cometary sources [e.g. 2]. The hydrated CS-IDPs show mineralogical similarities to heavily aqueously altered carbonaceous chondrites (e.g. CI chondrites), but only a few have been directly linked to carbonaceous meteorite parent bodies [e.g. 3, 4]. Most CS-IDPs show distinct chemical [5] and oxygen isotopic composition differences [6-8] from primitive carbonaceous chondrites. Here, we report on our coordinated analyses of a suite of carbon-rich CS-IDPs focusing on their bulk compositions, mineralogy, mineral chemistry, and isotopic compositions.

  8. Mineralogy and Oxygen Isotope Compositions of Two C-Rich Hydrated Interplanetary Dust Particles

    Science.gov (United States)

    Snead, C. J.; McKeegan, K. D.; Messenger, S.; Nakamura-Messenger, K.

    2012-01-01

    Oxygen isotopic compositions of chondrites reflect mixing between a O-16-rich reservoir and a O-17,O-18-rich reservoir produced via mass-independent fractionation. The composition of the O-16-rich reservoir is reasonably well constrained, but material representing the O-17,O-18-rich end-member is rare. Self-shielding models predict that cometary water, presumed to represent this reservoir, should be enriched in O-17 and O-18 18O by > 200%. Hydrated interplanetary dust particles (IDPs) rich in carbonaceous matter may be derived from comets; such particles likely contain the products of reaction between O-16-poor water and anhydrous silicates that formed in the inner solar system. Here we present mineralogy and oxygen isotope compositions of two C-rich hydrated IDPs, L2083E47 and L2071E35.

  9. Propagation of interplanetary shock waves by observations of type II solar radio bursts on IMP-6

    International Nuclear Information System (INIS)

    Chertok, I.M.; Fomichev, V.V.

    1976-01-01

    A new interpretation of the low frequency type II solar radio bursts of 30 June 1971, and 7-8 August 1972 observed with IMP-6 satellite (Malitson, H.H., Fainberg, J. and Stone, R.G., 1973, Astrophys. Lett., vol. 14, 111; Astrophys. J., vol. 183, L35) is suggested. The analysis is carried out for two models of the electron density distribution in the interplanetary medium taking into account that N approximately 3.5 cm -3 at a distance of 1 a.u. It is assumed that the frequency of the radio emission corresponds to the average electron density behind the shock front which exceeds the undisturbed electron density by the factor of 3. The radio data indicate essential deceleration of the shock waves during propagation from the Sun up to 1 a.u. The characteristics of the shock waves obtained from the type II bursts agree with the results of the in situ observations. (author)

  10. REDEFINING THE BOUNDARIES OF INTERPLANETARY CORONAL MASS EJECTIONS FROM OBSERVATIONS AT THE ECLIPTIC PLANE

    International Nuclear Information System (INIS)

    Cid, C.; Palacios, J.; Saiz, E.; Guerrero, A.

    2016-01-01

    On 2015 January 6–7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME offers a unique opportunity to check the boundaries’ process definition and to explain differences between them. Using Wind and ACE data, we perform a complementary analysis involving compositional, magnetic, and kinematic observations providing relevant information regarding the evolution of the ICME as travelling away from the Sun. We propose erosion, at least at the front boundary of the ICME, as the main reason for the difference between the boundaries, and compositional signatures as the most precise diagnostic tool for the boundaries of ICMEs.

  11. REDEFINING THE BOUNDARIES OF INTERPLANETARY CORONAL MASS EJECTIONS FROM OBSERVATIONS AT THE ECLIPTIC PLANE

    Energy Technology Data Exchange (ETDEWEB)

    Cid, C.; Palacios, J.; Saiz, E.; Guerrero, A. [Space Research Group—Space Weather, Departamento de Física y Matemáticas, Universidad de Alcalá, Alcalá de Henares (Spain)

    2016-09-01

    On 2015 January 6–7, an interplanetary coronal mass ejection (ICME) was observed at L1. This event, which can be associated with a weak and slow coronal mass ejection, allows us to discuss the differences between the boundaries of the magnetic cloud and the compositional boundaries. A fast stream from a solar coronal hole surrounding this ICME offers a unique opportunity to check the boundaries’ process definition and to explain differences between them. Using Wind and ACE data, we perform a complementary analysis involving compositional, magnetic, and kinematic observations providing relevant information regarding the evolution of the ICME as travelling away from the Sun. We propose erosion, at least at the front boundary of the ICME, as the main reason for the difference between the boundaries, and compositional signatures as the most precise diagnostic tool for the boundaries of ICMEs.

  12. The Distribution of Interplanetary Dust Near 1-AU: An MMS Perspective

    Science.gov (United States)

    Adrian, M. L.; St Cyr, O. C.; Wilson, L. B., III; Schiff, C.; Sacks, L. W.; Chai, D. J.; Queen, S. Z.; Sedlak, J. E.

    2017-12-01

    The distribution of dust in the ecliptic plane in the vicinity of 1-AU has been inferred from impacts on the four Magnetospheric Multiscale (MMS) mission spacecraft as detected by the Acceleration Measurement System (AMS) during periods when no other spacecraft activities are in progress. Consisting of four identically instrumented spacecraft, with an inter-spacecraft separation ranging from 10-km to 400-km, the MMS constellation forms a dust "detector" with approximately four-times the collection area of any previous dust monitoring framework. Here we introduce the MMS-AMS and the inferred dust impact observations, provide a preliminary comparison of the MMS distribution of dust impacts to previously reported interplanetary dust distributions — namely those of the STEREO mission — and report on our initial comparison of the MMS distribution of dust impacts with known meteor showers.

  13. Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun

    Science.gov (United States)

    Amenomori, M.; Bi, X. J.; Chen, D.; Chen, T. L.; Chen, W. Y.; Cui, S. W.; Danzengluobu, Ding, L. K.; Feng, C. F.; Feng, Zhaoyang; Feng, Z. Y.; Gou, Q. B.; Guo, Y. Q.; He, H. H.; He, Z. T.; Hibino, K.; Hotta, N.; Hu, Haibing; Hu, H. B.; Huang, J.; Jia, H. Y.; Jiang, L.; Kajino, F.; Kasahara, K.; Katayose, Y.; Kato, C.; Kawata, K.; Kozai, M.; Labaciren, Le, G. M.; Li, A. F.; Li, H. J.; Li, W. J.; Liu, C.; Liu, J. S.; Liu, M. Y.; Lu, H.; Meng, X. R.; Miyazaki, T.; Mizutani, K.; Munakata, K.; Nakajima, T.; Nakamura, Y.; Nanjo, H.; Nishizawa, M.; Niwa, T.; Ohnishi, M.; Ohta, I.; Ozawa, S.; Qian, X. L.; Qu, X. B.; Saito, T.; Saito, T. Y.; Sakata, M.; Sako, T. K.; Shao, J.; Shibata, M.; Shiomi, A.; Shirai, T.; Sugimoto, H.; Takita, M.; Tan, Y. H.; Tateyama, N.; Torii, S.; Tsuchiya, H.; Udo, S.; Wang, H.; Wu, H. R.; Xue, L.; Yamamoto, Y.; Yamauchi, K.; Yang, Z.; Yuan, A. F.; Yuda, T.; Zhai, L. M.; Zhang, H. M.; Zhang, J. L.; Zhang, X. Y.; Zhang, Y.; Zhang, Yi; Zhang, Ying; Zhaxisangzhu, Zhou, X. X.; Tibet AS γ Collaboration

    2018-01-01

    We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54 ±0.21stat±0.20syst (1.62 ±0.15stat±0.22syst ) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

  14. Three-dimensional exploration of the solar wind using observations of interplanetary scintillation.

    Science.gov (United States)

    Tokumaru, Munetoshi

    2013-01-01

    The solar wind, a supersonic plasma flow continuously emanating from the Sun, governs the space environment in a vast region extending to the boundary of the heliosphere (∼100 AU). Precise understanding of the solar wind is of importance not only because it will satisfy scientific interest in an enigmatic astrophysical phenomenon, but because it has broad impacts on relevant fields. Interplanetary scintillation (IPS) of compact radio sources at meter to centimeter wavelengths serves as a useful ground-based method for investigating the solar wind. IPS measurements of the solar wind at a frequency of 327 MHz have been carried out regularly since the 1980s using the multi-station system of the Solar-Terrestrial Environment Laboratory (STEL) of Nagoya University. This paper reviews new aspects of the solar wind revealed from our IPS observations.

  15. Winds in the high-latitude lower thermosphere: Dependence on the interplanetary magnetic field

    DEFF Research Database (Denmark)

    Richmond, A.D.; Lathuillere, C.; Vennerstrøm, Susanne

    2003-01-01

    of similar to20 hours, a B-y-dependent magnetic-zonal-mean zonal wind generally exists, with maximum wind speeds at 80 magnetic latitude, typically 10 m/s at 105 km, increasing to about 60 m/s at 123 km and 80 m/s at 200 km. In the southern hemisphere the wind is cyclonic when the time-averaged B-y......[1] Wind observations in the summertime lower thermosphere at high southern latitudes, measured by the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite, are statistically analyzed in magnetic coordinates and correlated with the interplanetary magnetic field (IMF......) to determine influences of IMF-dependent ionospheric convection on the winds. Effects are clearly detectable down to 105 km altitude. Above 125 km the wind patterns show considerable similarity with ionospheric convection patterns, and the speed of the averaged neutral wind in the polar cap often exceeds 300 m...

  16. Instrument to measure energy and charge of low energy interplanetary particles

    Science.gov (United States)

    Tums, E.; Gloeckler, G.; Cain, J.; Sciambi, R.; Fan, C. Y.

    1974-01-01

    An experiment to measure the charge composition and energy spectra of ultra low energy charged particles in interplanetary space has been developed and launched on the IMP 8 (Explorer 50) satellite on Oct. 26, 1973. The instrument consists of two separate sensors sharing common electronics. One of these sensors uses a thin window gas proportional counter to measure the rate of energy loss and a totally depleted silicon surface barrier detector to measure total energy of incoming particles. The energy range for two dimensional analysis extends from 300 KeV to 2.5 MeV for protons and 60 KeV/nucleon to 25 MeV/nucleon for iron with excellent resolution of individual chemical elements. The other sensor combines electrostatic deflection with total energy measurements in silicon surface barrier detectors to give the ionic charge and kinetic energy of the particle.

  17. Comparison of single event upset rates for microelectronic memory devices during interplanetary solar particle events

    Science.gov (United States)

    Mckerracher, P. L.; Kinnison, J. D.; Maurer, R. H.

    1993-01-01

    Variability in the methods and models used for single event upset calculations in microelectronic memory devices can lead to a range of possible upset rates. Using heavy ion and proton data for selected DRAM and SRAM memories, we have calculated an array of upset rates in order to compare the Adams worst case interplanetary solar flare model to a model proposed by scientists at the Jet Propulsion Laboratory. In addition, methods of upset rate calculation are compared: the Cosmic Ray Effects on Microelectronics CREME code and a Monte Carlo algorithm developed at the Applied Physics Laboratory. The results show that use of a more realistic, although still conservative, model of the space environment can have significant cost saving benefits.

  18. Rapid Preliminary Design of Interplanetary Trajectories Using the Evolutionary Mission Trajectory Generator

    Science.gov (United States)

    Englander, Jacob

    2016-01-01

    Preliminary design of interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated. This can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on notional high-thrust chemical and low-thrust electric propulsion missions. In the low-thrust case, the hybrid optimal control problem is augmented to include systems design optimization.

  19. Global Optimization of Low-Thrust Interplanetary Trajectories Subject to Operational Constraints

    Science.gov (United States)

    Englander, Jacob A.; Vavrina, Matthew A.; Hinckley, David

    2016-01-01

    Low-thrust interplanetary space missions are highly complex and there can be many locally optimal solutions. While several techniques exist to search for globally optimal solutions to low-thrust trajectory design problems, they are typically limited to unconstrained trajectories. The operational design community in turn has largely avoided using such techniques and has primarily focused on accurate constrained local optimization combined with grid searches and intuitive design processes at the expense of efficient exploration of the global design space. This work is an attempt to bridge the gap between the global optimization and operational design communities by presenting a mathematical framework for global optimization of low-thrust trajectories subject to complex constraints including the targeting of planetary landing sites, a solar range constraint to simplify the thermal design of the spacecraft, and a real-world multi-thruster electric propulsion system that must switch thrusters on and off as available power changes over the course of a mission.

  20. Shielding from cosmic radiation for interplanetary missions Active and passive methods

    CERN Document Server

    Spillantini, P; Durante, M; Müller-Mellin, R; Reitz, G; Rossi, L; Shurshakov, V; Sorbi, M

    2007-01-01

    Shielding is arguably the main countermeasure for the exposure to cosmic radiation during interplanetary exploratory missions. However, shielding of cosmic rays, both of galactic or solar origin, is problematic, because of the high energy of the charged particles involved and the nuclear fragmentation occurring in shielding materials. Although computer codes can predict the shield performance in space, there is a lack of biological and physical measurements to benchmark the codes. An attractive alternative to passive, bulk material shielding is the use of electromagnetic fields to deflect the charged particles from the spacecraft target. Active shielding concepts based on electrostatic fields, plasma, or magnetic fields have been proposed in the past years, and should be revised based on recent technological improvements. To address these issues, the European Space Agency (ESA) established a Topical Team (TT) in 2002 including European experts in the field of space radiation shielding and superconducting magn...

  1. Linear Response of Field-Aligned Currents to the Interplanetary Electric Field

    DEFF Research Database (Denmark)

    Weimer, D. R.; R. Edwards, T.; Olsen, Nils

    2017-01-01

    Many studies that have shown that the ionospheric, polar cap electric potentials (PCEP) exhibit a “saturation” behavior in response to the level of the driving by the solar wind. As the magnitude of the interplanetary magnetic field (IMF) and electric field (IEF) increase, the PCEP response...... of the field-aligned currents (FAC) with the solar wind/magnetosphere/ionosphere system has a role. As the FAC are more difficult to measure, their behavior in response to the level of the IEF has not been investigated as thoroughly. In order to resolve the question of whether or not the FAC also exhibit...... saturation, we have processed the magnetic field measurements from the Ørsted, CHAMP, and Swarm missions, spanning more than a decade. As the amount of current in each region needs to be known, a new technique is used to separate and sum the current by region, widely known as R0, R1, and R2. These totals...

  2. An Automated Solution of the Low-Thrust Interplanetary Trajectory Problem

    Science.gov (United States)

    Englander, Jacob A.; Conway, Bruce

    2016-01-01

    Preliminary design of low-thrust interplanetary missions is a highly complex process. The mission designer must choose discrete parameters such as the number of flybys, the bodies at which those flybys are performed, and in some cases the final destination. In addition, a time-history of control variables must be chosen that defines the trajectory. There are often many thousands, if not millions, of possible trajectories to be evaluated, which can be a very expensive process in terms of the number of human analyst hours required. An automated approach is therefore very desirable. This work presents such an approach by posing the mission design problem as a hybrid optimal control problem. The method is demonstrated on hypothetical missions to Mercury, the main asteroid belt, and Pluto.

  3. How Interplanetary Scintillation Data Can Improve Modeling of Coronal Mass Ejection Propagation

    Science.gov (United States)

    Taktakishvili, A.; Mays, M. L.; Manoharan, P. K.; Rastaetter, L.; Kuznetsova, M. M.

    2017-12-01

    Coronal mass ejections (CMEs) can have a significant impact on the Earth's magnetosphere-ionosphere system and cause widespread anomalies for satellites from geosynchronous to low-Earth orbit and produce effects such as geomagnetically induced currents. At the NASA/GSFC Community Coordinated Modeling Center we have been using ensemble modeling of CMEs since 2012. In this presnetation we demonstrate that using of interplanetary scintillation (IPS) observations from the Ooty Radio Telescope facility in India can help to track CME propagaion and improve ensemble forecasting of CMEs. The observations of the solar wind density and velocity using IPS from hundreds of distant sources in ensemble modeling of CMEs can be a game-changing improvement of the current state of the art in CME forecasting.

  4. Interplanetary outpost the human and technological challenges of exploring the outer planets

    CERN Document Server

    Seedhouse, Erik

    2012-01-01

    Water has been discovered on the Saturnian moon, Enceladus, and on Jupiter's moons, Europa, Ganymede, and Callisto. Where there is water, could there be life? Could this tantalizing possibility result in a manned mission to the outer planets? But how will such a mission be designed, what propulsion system will be used, and what hazards will the crewmembers face? Interplanetary Outpost describes step by step how the mission architecture will evolve, how crews will be selected and trained, and what the mission will entail from launch to landing. It addresses the effects that exteneded duration, radiation, communication, and isolation will have on the human body, and how not only performance but behavior might be affected.

  5. A theoretical perspective on particle acceleration by interplanetary shocks and the Solar Energetic Particle problem

    Science.gov (United States)

    Verkhoglyadova, Olga P.; Zank, Gary P.; Li, Gang

    2015-02-01

    Understanding the physics of Solar Energetic Particle (SEP) events is of importance to the general question of particle energization throughout the cosmos as well as playing a role in the technologically critical impact of space weather on society. The largest, and often most damaging, events are the so-called gradual SEP events, generally associated with shock waves driven by coronal mass ejections (CMEs). We review the current state of knowledge about particle acceleration at evolving interplanetary shocks with application to SEP events that occur in the inner heliosphere. Starting with a brief outline of recent theoretical progress in the field, we focus on current observational evidence that challenges conventional models of SEP events, including complex particle energy spectra, the blurring of the distinction between gradual and impulsive events, and the difference inherent in particle acceleration at quasi-parallel and quasi-perpendicular shocks. We also review the important problem of the seed particle population and its injection into particle acceleration at a shock. We begin by discussing the properties and characteristics of non-relativistic interplanetary shocks, from their formation close to the Sun to subsequent evolution through the inner heliosphere. The association of gradual SEP events with shocks is discussed. Several approaches to the energization of particles have been proposed, including shock drift acceleration, diffusive shock acceleration (DSA), acceleration by large-scale compression regions, acceleration by random velocity fluctuations (sometimes known as the "pump mechanism"), and others. We review these various mechanisms briefly and focus on the DSA mechanism. Much of our emphasis will be on our current understanding of the parallel and perpendicular diffusion coefficients for energetic particles and models of plasma turbulence in the vicinity of the shock. Because of its importance both to the DSA mechanism itself and to the particle

  6. Dynamic response of the Martian ionosphere to an interplanetary shock: Mars Express and MAVEN observations

    Science.gov (United States)

    Harada, Y.; Gurnett, D. A.; Kopf, A. J.; Halekas, J. S.; Ruhunusiri, S.; Lee, C. O.; Hara, T.; Espley, J.; DiBraccio, G. A.; Mitchell, D. L.; Mazelle, C.; Larson, D. E.; Jakosky, B. M.

    2017-09-01

    Multipoint observations from the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument on board Mars Express and the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission reveal a dynamic response of the Martian ionosphere to abrupt variations in the upstream solar wind plasma. On 2 February 2017, MAVEN, located upstream from the Martian bow shock, encountered a corotating interaction region-related interplanetary shock with a sudden enhancement in the dynamic pressure. MARSIS, operating in the upper ionosphere at ˜478 km altitudes and ˜78° solar zenith angles, observed a sharp increase in the local magnetic field magnitude ˜1 min after the shock passage at MAVEN. The time lag is roughly consistent with the expected propagation time of a pressure pulse from the bow shock to the upper ionosphere at the fast magnetosonic speed. Subsequently, remote soundings recorded disturbed signatures of the topside ionosphere below Mars Express.

  7. Prospective Out-of-ecliptic White-light Imaging of Interplanetary Corotating Interaction Regions at Solar Maximum

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ming; Yang, Liping; Liu, Ying D.; Keiji, Hayashi; Li, Huichao [State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Davies, Jackie A.; Harrison, Richard A. [RAL Space, STFC-Rutherford Appleton Laboratory, Harwell Campus, Didcot (United Kingdom); Li, Bo; Xia, Lidong, E-mail: mxiong@spacweather.ac.cn [Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment, Institute of Space Sciences, Shandong University, Weihai (China)

    2017-07-20

    Interplanetary corotating interaction regions (CIRs) can be remotely imaged in white light (WL), as demonstrated by the Solar Mass Ejection Imager (SMEI) on board the Coriolis spacecraft and Heliospheric Imagers (HIs) on board the twin Solar TErrestrial RElations Observatory ( STEREO ) spacecraft. The interplanetary WL intensity, due to Thomson scattering of incident sunlight by free electrons, is jointly determined by the 3D distribution of electron number density and line-of-sight (LOS) weighting factors of the Thomson-scattering geometry. The 2D radiance patterns of CIRs in WL sky maps look very different from different 3D viewpoints. Because of the in-ecliptic locations of both the STEREO and Coriolis spacecraft, the longitudinal dimension of interplanetary CIRs has, up to now, always been integrated in WL imagery. To synthesize the WL radiance patterns of CIRs from an out-of-ecliptic (OOE) vantage point, we perform forward magnetohydrodynamic modeling of the 3D inner heliosphere during Carrington Rotation CR1967 at solar maximum. The mixing effects associated with viewing 3D CIRs are significantly minimized from an OOE viewpoint. Our forward modeling results demonstrate that OOE WL imaging from a latitude greater than 60° can (1) enable the garden-hose spiral morphology of CIRs to be readily resolved, (2) enable multiple coexisting CIRs to be differentiated, and (3) enable the continuous tracing of any interplanetary CIR back toward its coronal source. In particular, an OOE view in WL can reveal where nascent CIRs are formed in the extended corona and how these CIRs develop in interplanetary space. Therefore, a panoramic view from a suite of wide-field WL imagers in a solar polar orbit would be invaluable in unambiguously resolving the large-scale longitudinal structure of CIRs in the 3D inner heliosphere.

  8. Non-Uniqueness of the Geometry of Interplanetary Magnetic Flux Ropes Obtained from Model-Fitting

    Science.gov (United States)

    Marubashi, K.; Cho, K.-S.

    2015-12-01

    Since the early recognition of the important role of interplanetary magnetic flux ropes (IPFRs) to carry the southward magnetic fields to the Earth, many attempts have been made to determine the structure of the IPFRs by model-fitting analyses to the interplanetary magnetic field variations. This paper describes the results of fitting analyses for three selected solar wind structures in the latter half of 2014. In the fitting analysis a special attention was paid to identification of all the possible models or geometries that can reproduce the observed magnetic field variation. As a result, three or four geometries have been found for each of the three cases. The non-uniqueness of the fitted results include (1) the different geometries naturally stemming from the difference in the models used for fitting, and (2) an unexpected result that either of magnetic field chirality, left-handed and right-handed, can reproduce the observation in some cases. Thus we conclude that the model-fitting cannot always give us a unique geometry of the observed magnetic flux rope. In addition, we have found that the magnetic field chirality of a flux rope cannot be uniquely inferred from the sense of field vector rotation observed in the plane normal to the Earth-Sun line; the sense of rotation changes depending on the direction of the flux rope axis. These findings exert an important impact on the studies aimed at the geometrical relationships between the flux ropes and the magnetic field structures in the solar corona where the flux ropes were produced, such studies being an important step toward predicting geomagnetic storms based on observations of solar eruption phenomena.

  9. Interplanetary Magnetic Flux Ropes as Agents Connecting Solar Eruptions and Geomagnetic Activities

    Science.gov (United States)

    Marubashi, K.; Cho, K.-S.; Ishibashi, H.

    2017-12-01

    We investigate the solar wind structure for 11 cases that were selected for the campaign study promoted by the International Study of Earth-affecting Solar Transients (ISEST) MiniMax24 Working Group 4. We can identify clear flux rope signatures in nine cases. The geometries of the nine interplanetary magnetic flux ropes (IFRs) are examined with a model-fitting analysis with cylindrical and toroidal force-free flux rope models. For seven cases in which magnetic fields in the solar source regions were observed, we compare the IFR geometries with magnetic structures in their solar source regions. As a result, we can confirm the coincidence between the IFR orientation and the orientation of the magnetic polarity inversion line (PIL) for six cases, as well as the so-called helicity rule as regards the handedness of the magnetic chirality of the IFR, depending on which hemisphere of the Sun the IFR originated from, the northern or southern hemisphere; namely, the IFR has right-handed (left-handed) magnetic chirality when it is formed in the southern (northern) hemisphere of the Sun. The relationship between the orientation of IFRs and PILs can be taken as evidence that the flux rope structure created in the corona is in most cases carried through interplanetary space with its orientation maintained. In order to predict magnetic field variations on Earth from observations of solar eruptions, further studies are needed about the propagation of IFRs because magnetic fields observed at Earth significantly change depending on which part of the IFR hits the Earth.

  10. The F-region trough: seasonal morphology and relation to interplanetary magnetic field

    Directory of Open Access Journals (Sweden)

    M. Voiculescu

    2006-03-01

    Full Text Available We present here the results of a statistical study of the ionospheric trough observed in 2003 by means of satellite tomography. We focus on the seasonal morphology of the trough occurrence and investigate the trough latitude, width and the horizontal gradients at the edges, at different magnetic local times, as well as their relations to geomagnetic activity and the interplanetary magnetic field. A seasonal effect is noticed in the diurnal variation of the trough latitude, indicating that summer clearly differs from the other seasons. In winter the troughs seem to follow the solar terminator. The width of the trough has a diurnal variation and it depends on the season, as well. The broadest troughs are observed in winter and the narrowest ones in summer. A discontinuity in the diurnal variation of the trough latitude is observed before noon. It is suggested that this is an indication of a difference between the generation mechanisms of morningside and eveningside troughs. The density gradients at the edges have a complex dependence on the latitude of the trough and on geomagnetic activity. The photoionization and the auroral precipitation are competing in the formation of the trough walls at different magnetic local times. An important finding is that the interplanetary magnetic field plays a role in the occurrence of the trough at different levels of geomagnetic activity. This is probably associated with the topology of the polar cap convection pattern, which depends on the directions of the IMF components By and Bz.

  11. Evolution of magnetic flux ropes associated with flux transfer events and interplanetary magnetic clouds

    International Nuclear Information System (INIS)

    Wei, C.Q.; Lee, L.C.; Wang, S.; Akasofu, S.I.

    1991-01-01

    Spacecraft observations suggest that flux transfer events and interplanetary magnetic clouds may be associated with magnetic flux ropes which are magnetic flux tubes containing helical magnetic field lines. In the magnetic flux ropes, the azimuthal magnetic field (B θ ) is superposed on the axial field (B z ). In this paper the time evolution of a localized magnetic flux rope is studied. A two-dimensional compressible magnetohydrodynamic simulation code with a cylindrical symmetry is developed to study the wave modes associated with the evolution of flux ropes. It is found that in the initial phase both the fast magnetosonic wave and the Alfven wave are developed in the flux rope. After this initial phase, the Alfven wave becomes the dominant wave mode for the evolution of the magnetic flux rope and the radial expansion velocity of the flux rope is found to be negligible. Numerical results further show that even for a large initial azimuthal component of the magnetic field (B θ ≅ 1-4 B z ) the propagation velocity along the axial direction of the flux rope remains to be the Alfven velocity. Diagnoses show that after the initial phase the transverse kinetic energy equals the transverse magnetic energy, which is characteristic of the Alfven mode. It is also found that the localized magnetic flux rope tends to evolve into two separate magnetic ropes propagating in opposite directions. The simulation results are used to study the evolution of magnetic flux ropes associated with flux transfer events observed at the Earth's dayside magnetopause and magnetic clouds in the interplanetary space

  12. Relationship between PC index and interplanetary electric field EKL under actual conditions of varying solar wind

    Science.gov (United States)

    Troshichev, Oleg; Smirnov, Michael

    The PC index was introduced as an indicator of magnetic activity in the polar caps generated by the geoeffective interplanetary electric field E _{KL} determined in accordance with Kan and Lee [1979]. The PC index is calculated basing on magnetic data (δF) from near-pole stations Thule and Vostok with use of the statistically justified coefficients of regression α and β linking the polar cap magnetic disturbance vectors δF with the electric field E _{KL}. As a result, the PC index is defined as a value of the polar cap magnetic disturbance standardized with the intensity of the interplanetary electric field EKL regardless of season, UT and hemisphere. Statistically the appropriate values PC and E _{KL} well correlate, however in concrete situations PC and E _{KL} may be quite differ, because E _{KL} characterizes the state of the solar wind far upstream of the magnetosphere, whereas PC characterizes the energy that entered into magnetosphere, Analysis of consistencies and discrepancies between PC and E _{KL} under conditions of different solar wind parameters was carried for all events with magnetic substorms (N=1798) and magnetic storms (N=203) observed in epoch of maximal solar activity (1998-2001). Thus, the solar wind geoefficiency was estimated by independent indicators, such as AL and Dst indices characterizing magnetic activity within the magnetosphere. The essential attention was given also to geoefficiency of sudden pulses of the solar wind dynamic pressure. The results of the analysis were applied to derive the method to nowcast the magnetosphere state, including estimation of the “model PC, AL and Dst” indices calculated by actual measurement of E _{KL} in the point L1 under conditions of varying solar wind. It is demonstrated that the PC index can be successfully used to monitor space weather and the readiness of the magnetosphere to producing substorm or storm.

  13. Fuzzy Behavior Modulation with Threshold Activation for Autonomous Vehicle Navigation

    Science.gov (United States)

    Tunstel, Edward

    2000-01-01

    This paper describes fuzzy logic techniques used in a hierarchical behavior-based architecture for robot navigation. An architectural feature for threshold activation of fuzzy-behaviors is emphasized, which is potentially useful for tuning navigation performance in real world applications. The target application is autonomous local navigation of a small planetary rover. Threshold activation of low-level navigation behaviors is the primary focus. A preliminary assessment of its impact on local navigation performance is provided based on computer simulations.

  14. E-navigation Services for Non-SOLAS Ships

    Directory of Open Access Journals (Sweden)

    Kwang An

    2016-06-01

    Full Text Available It is clearly understood that the main benefits of e-navigation are improved safety and better protection of the environment through the promotion of standards of navigational system and a reduction in human error. In order to meet the expectations on the benefit of e-navigation, e-navigation services should be more focused on non-SOLAS ships. The purpose of this paper is to present necessary e-navigation services for non-SOLAS ships in order to prevent marine accidents in Korean coastal waters. To meet the objectives of the study, an examination on the present navigation and communication system for non-SOLAS ships was performed. Based on the IMO's e-navigation Strategy Implementation Plan (SIP and Korea's national SIP for e-navigation, future trends for the development and implementation of e-navigation were discussed. Consequently, Electronic Navigational Chart (ENC download and ENC up-date service, ENC streaming service, route support service and communication support service based on Maritime Cloud were presented as essential e-navigation services for non-SOLAS ships. This study will help for the planning and designing of the Korean e-navigation system. It is expected that the further researches on the navigation support systems based on e-navigation will be carried out in order to implement the essential e-navigation services for non-SOLAS ships.

  15. Integrated navigation method of a marine strapdown inertial navigation system using a star sensor

    International Nuclear Information System (INIS)

    Wang, Qiuying; Diao, Ming; Gao, Wei; Zhu, Minghong; Xiao, Shu

    2015-01-01

    This paper presents an integrated navigation method of the strapdown inertial navigation system (SINS) using a star sensor. According to the principle of SINS, its own navigation information contains an error that increases with time. Hence, the inertial attitude matrix from the star sensor is introduced as the reference information to correct the SINS increases error. For the integrated navigation method, the vehicle’s attitude can be obtained in two ways: one is calculated from SINS; the other, which we have called star sensor attitude, is obtained as the product between the SINS position and the inertial attitude matrix from the star sensor. Therefore, the SINS position error is introduced in the star sensor attitude error. Based on the characteristics of star sensor attitude error and the mathematical derivation, the SINS navigation errors can be obtained by the coupling calculation between the SINS attitude and the star sensor attitude. Unlike several current techniques, the navigation process of this method is non-radiating and invulnerable to jamming. The effectiveness of this approach was demonstrated by simulation and experimental study. The results show that this integrated navigation method can estimate the attitude error and the position error of SINS. Therefore, the SINS navigation accuracy is improved. (paper)

  16. 75 FR 50884 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-18

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 3 and 165 [Docket No. USCG-2010-0351] RIN 1625-ZA25 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector... Waters; Technical, Organizational, and Conforming Amendments, Sector Columbia River.'' 2. On page 48564...

  17. 78 FR 41304 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Correction

    Science.gov (United States)

    2013-07-10

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 105 [Docket No. USCG-2013-0397] RIN 1625-AC06 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments; Correction AGENCY: Coast Guard, DHS. ACTION: Final rule; correction. SUMMARY: The Coast Guard published a final rule...

  18. 75 FR 48564 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-11

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 3 and 165 [Docket No. USCG-2010-0351] RIN 1625-ZA25 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector Columbia River, WA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: This rule makes non-substantive...

  19. 75 FR 58304 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-09-24

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 3 [Docket No. USCG-2010-0351] RIN 1625-ZA25 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector Puget Sound, WA; Correction AGENCY: Coast Guard, DHS. ACTION: Final rule; correction. SUMMARY: The Coast...

  20. 75 FR 47211 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector...

    Science.gov (United States)

    2010-08-05

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Parts 3 and 165 [Docket No. USCG-2010-0351] RIN 1625-ZA25 Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments, Sector Puget Sound, WA AGENCY: Coast Guard, DHS. ACTION: Final rule. SUMMARY: This rule makes non-substantive...

  1. 78 FR 39163 - Navigation and Navigable Waters; Technical, Organizational, and Conforming Amendments

    Science.gov (United States)

    2013-07-01

    ... protection, Harbors, Petroleum. 33 CFR Part 149 Fire prevention, Harbors, Marine safety, Navigation (water), Occupational safety and health, Oil pollution. 33 CFR Part 150 Harbors, Marine safety, Navigation (water.... This rule amends Sec. 138.45 to update contact phone numbers at the National Pollution Funds Center...

  2. Target relative navigation results from hardware-in-the-loop tests using the sinplex navigation system

    NARCIS (Netherlands)

    Steffes, S.; Dumke, M.; Heise, D.; Sagliano, M.; Samaan, M.; Theil, S.; Boslooper, E.C.; Oosterling, J.A.J.; Schulte, J.; Skaborn, D.; Söderholm, S.; Conticello, S.; Esposito, M.; Yanson, Y.; Monna, B.; Stelwagen, F.; Visee, R.

    2014-01-01

    The goal of the SINPLEX project is to develop an innovative solution to significantly reduce the mass of the navigation subsystem for exploration missions which include landing and/or rendezvous and capture phases. The system mass is reduced while still maintaining good navigation performance as

  3. Intelligent navigation to improve obstetrical sonography.

    Science.gov (United States)

    Yeo, Lami; Romero, Roberto

    2016-04-01

    'Manual navigation' by the operator is the standard method used to obtain information from two-dimensional and volumetric sonography. Two-dimensional sonography is highly operator dependent and requires extensive training and expertise to assess fetal anatomy properly. Most of the sonographic examination time is devoted to acquisition of images, while 'retrieval' and display of diagnostic planes occurs rapidly (essentially instantaneously). In contrast, volumetric sonography has a rapid acquisition phase, but the retrieval and display of relevant diagnostic planes is often time-consuming, tedious and challenging. We propose the term 'intelligent navigation' to refer to a new method of interrogation of a volume dataset whereby identification and selection of key anatomical landmarks allow the system to: 1) generate a geometrical reconstruction of the organ of interest; and 2) automatically navigate, find, extract and display specific diagnostic planes. This is accomplished using operator-independent algorithms that are both predictable and adaptive. Virtual Intelligent Sonographer Assistance (VIS-Assistance®) is a tool that allows operator-independent sonographic navigation and exploration of the surrounding structures in previously identified diagnostic planes. The advantage of intelligent (over manual) navigation in volumetric sonography is the short time required for both acquisition and retrieval and display of diagnostic planes. Intelligent navigation technology automatically realigns the volume, and reorients and standardizes the anatomical position, so that the fetus and the diagnostic planes are consistently displayed in the same manner each time, regardless of the fetal position or the initial orientation. Automatic labeling of anatomical structures, subject orientation and each of the diagnostic planes is also possible. Intelligent navigation technology can operate on conventional computers, and is not dependent on specific ultrasound platforms or on the

  4. 33 CFR 66.05-25 - Change and modification of State aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... aids to navigation. 66.05-25 Section 66.05-25 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-25 Change and modification of State aids to navigation. Wherever a State Administrator determines the...

  5. 33 CFR 66.01-50 - Protection of private aids to navigation.

    Science.gov (United States)

    2010-07-01

    ... SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION Aids to Navigation Other Than Federal or State § 66.01-50 Protection of private aids to navigation. Private aids to navigation lawfully maintained under... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Protection of private aids to...

  6. 33 CFR 66.05-35 - Private aids to navigation other than State owned.

    Science.gov (United States)

    2010-07-01

    ... HOMELAND SECURITY AIDS TO NAVIGATION PRIVATE AIDS TO NAVIGATION State Aids to Navigation § 66.05-35 Private... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Private aids to navigation other... States, shall establish, erect or maintain in State waters for private aids to navigation any aid to...

  7. Global navigation satellite system; Jisedai kokoho senjo system

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, S.; Suga, S. [Toshiba Corp., Tokyo (Japan)

    2000-05-01

    The safety of civil aviation relies on ground navigation aids. In areas where there are no ground aids and on oceanic air routes, aircraft must depend on their own navigation system. The predicted increase in civil aviation traffic in the near future will make it difficult for current navigation aids to support navigation in all phases of flights. To avoid this problem, the International Civil Aviation Organization (ICAO) is directing the establishment of standards for the global navigation satellite system (GNSS). GNSS employs navigation satellites, such as those of the global positioning system (GPS), to provide navigation capability throughout the world. In Japan, the Electronic Navigation Research Institute, the Ministry of Transport, and the Japan civil Aviation Promotion Foundation are carrying out research on this navigation system. Toshiba has been providing experimental equipment for this research. (author)

  8. Benchmark Framework for Mobile Robots Navigation Algorithms

    Directory of Open Access Journals (Sweden)

    Nelson David Muñoz-Ceballos

    2014-01-01

    Full Text Available Despite the wide variety of studies and research on mobile robot systems, performance metrics are not often examined. This makes difficult to establish an objective comparison of achievements. In this paper, the navigation of an autonomous mobile robot is evaluated. Several metrics are described. These metrics, collectively, provide an indication of navigation quality, useful for comparing and analyzing navigation algorithms of mobile robots. This method is suggested as an educational tool, which allows the student to optimize the algorithms quality, relating to important aspectsof science, technology and engineering teaching, as energy consumption, optimization and design.

  9. Mobile Robot Designed with Autonomous Navigation System

    Science.gov (United States)

    An, Feng; Chen, Qiang; Zha, Yanfang; Tao, Wenyin

    2017-10-01

    With the rapid development of robot technology, robots appear more and more in all aspects of life and social production, people also ask more requirements for the robot, one is that robot capable of autonomous navigation, can recognize the road. Take the common household sweeping robot as an example, which could avoid obstacles, clean the ground and automatically find the charging place; Another example is AGV tracking car, which can following the route and reach the destination successfully. This paper introduces a new type of robot navigation scheme: SLAM, which can build the environment map in a totally strange environment, and at the same time, locate its own position, so as to achieve autonomous navigation function.

  10. Terrain Adaptive Navigation for Mars Rovers

    Science.gov (United States)

    Matthies, Larry H.; Helmick, Daniel M.; Angelova, Anelia; Livianu, Matthew

    2007-01-01

    A navigation system for Mars rovers in very rough terrain has been designed, implemented, and tested on a research rover in Mars analog terrain. This navigation system consists of several technologies that are integrated to increase the capabilities compared to current rover navigation algorithms. These technologies include: goodness maps and terrain triage, terrain classification, remote slip prediction, path planning, high-fidelity traversability analysis (HFTA), and slip-compensated path following. The focus of this paper is not on the component technologies, but rather on the integration of these components. Results from the onboard integration of several of the key technologies described here are shown. Additionally, the results from independent demonstrations of several of these technologies are shown. Future work will include the demonstration of the entire integrated system described here.

  11. Cloud Absorption Radiometer Autonomous Navigation System - CANS

    Science.gov (United States)

    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

  12. Wavefront Propagation and Fuzzy Based Autonomous Navigation

    Directory of Open Access Journals (Sweden)

    Adel Al-Jumaily

    2005-06-01

    Full Text Available Path planning and obstacle avoidance are the two major issues in any navigation system. Wavefront propagation algorithm, as a good path planner, can be used to determine an optimal path. Obstacle avoidance can be achieved using possibility theory. Combining these two functions enable a robot to autonomously navigate to its destination. This paper presents the approach and results in implementing an autonomous navigation system for an indoor mobile robot. The system developed is based on a laser sensor used to retrieve data to update a two dimensional world model of therobot environment. Waypoints in the path are incorporated into the obstacle avoidance. Features such as ageing of objects and smooth motion planning are implemented to enhance efficiency and also to cater for dynamic environments.

  13. Navigation of robotic system using cricket motes

    Science.gov (United States)

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

    2011-06-01

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

  14. Polarimetry of Dust in Optically Thin Clouds: Observations and Experimental Simulations of Cometary and Interplanetary Dust

    Science.gov (United States)

    Hadamcik, E.; Renard, J.; Levasseur-Regourd, A.; Lasue, J.

    2013-12-01

    Remote polarimetric observations are used to tentatively infer the physical properties of the dust particles in cometary and interplanetary environments. To interpret the results, numerical and experimental simulations are necessary. Light scattering measurements on levitating particles with the PROGRA2 experiment -in dedicated microgravity flights or in the laboratory for low-density particles- provide relevant simulations of the scattering properties of real particles, which can present large size distributions and a large variety of structures and materials (Renard et al., 2002; Hadamcik et al., 2009). Previous systematic experiments, together with numerical models and laboratory analysis of cosmic particles (e.g. Stardust samples) allow to optimize dust particles' properties -such as their structures, sizes, size distributions, and silicate to organics ratios- (Hadamcik et al. 2007a; Zubko et al., 2009; Lasue et al., 2010). We present intensity and polarization images of cometary comae providing evidence for changes in the polarization properties in the internal regions of the coma, linked to the variation of particles properties with nucleus distance and/or rotation phase (Hadamcik et al., 2007a; Hadamcik et al., 2013a; 2013b) and preliminary results of 2013 observations. Associated experimental simulations help us to interpret how particles evolve within different coma regions and at different solar distances (Hadamcik et al. 2007b; 2009; 2011). We expect in situ confirmation of our results during the Rosetta mission to comet 67P/Churyumov-Gerasimenko in 2014-2015 (Hadamcik et al., 2010). Analyses of observations of the zodiacal light scattered by the interplanetary dust cloud particles have shown local polarisation changes with the solar distance (Levasseur-Regourd et al., 2001). Such changes are interpreted through numerical models to be related to variations in the composition and physical properties of the particles through various processes including

  15. High accuracy GNSS based navigation in GEO

    Science.gov (United States)

    Capuano, Vincenzo; Shehaj, Endrit; Blunt, Paul; Botteron, Cyril; Farine, Pierre-André

    2017-07-01

    Although significant improvements in efficiency and performance of communication satellites have been achieved in the past decades, it is expected that the demand for new platforms in Geostationary Orbit (GEO) and for the On-Orbit Servicing (OOS) on the existing ones will continue to rise. Indeed, the GEO orbit is used for many applications including direct broadcast as well as communications. At the same time, Global Navigation Satellites System (GNSS), originally designed for land, maritime and air applications, has been successfully used as navigation system in Low Earth Orbit (LEO) and its further utilization for navigation of geosynchronous satellites becomes a viable alternative offering many advantages over present ground based methods. Following our previous studies of GNSS signal characteristics in Medium Earth Orbit (MEO), GEO and beyond, in this research we specifically investigate the processing of different GNSS signals, with the goal to determine the best navigation performance they can provide in a GEO mission. Firstly, a detailed selection among different GNSS signals and different combinations of them is discussed, taking into consideration the L1 and L5 frequency bands, and the GPS and Galileo constellations. Then, the implementation of an Orbital Filter is summarized, which adaptively fuses the GN1SS observations with an accurate orbital forces model. Finally, simulation tests of the navigation performance achievable by processing the selected combination of GNSS signals are carried out. The results obtained show an achievable positioning accuracy of less than one meter. In addition, hardware-in-the-loop tests are presented using a COTS receiver connected to our GNSS Spirent simulator, in order to collect real-time hardware-in-the-loop observations and process them by the proposed navigation module.

  16. Representing User Navigation in XML Retrieval with Structural Summaries

    DEFF Research Database (Denmark)

    Ali, M. S.; Consens, Mariano P.; Larsen, Birger

    This poster presents a novel way to represent user navigation in XML retrieval using collection statistics from XML summaries. Currently, developing user navigation models in XML retrieval is costly and the models are specific to collected user assessments. We address this problem by proposing...... summary navigation models which describe user navigation in terms of XML summaries. We develop our proposal using assessments collected in the interactive track at INEX 2006. Our preliminary results suggest that summary navigation models can represent user navigation in a way that is e ective...

  17. Dayside Global Ionospheric Response to the Major Interplanetary Events of October 29-30, 2003 ''Halloween Storms''

    Science.gov (United States)

    Mannucci, A. J.; Tsurutani, B. T.; Iijima, B. A.; Komjathy, A.; Saito, A.; Gonzalez, W. D.; Guarnieri, F. L.; Kozyra, J. U.; Skoug, R.

    2005-01-01

    We demonstrate extreme ionospheric response to the large interplanetary electric fields during the "Halloween" storms that occurred on October 29 and 30, 2003. Within a few (2 - 5) hours of the time when the enhanced interplanetary electric field impinged on the magnetopause, dayside total electron content increases of approx.40% and approx.250% are observed for the October 29 and 30 events, respectively. During the Oct 30 event, approx.900% increases in electron content above the CHAMP satellite (approx.400 km altitude) were observed at mid-latitudes (+/-30 degrees geomagnetic). The geomagnetic storm-time phenomenon of prompt penetration electric fields is a possible contributing cause of these electron content increases, producing dayside ionospheric uplift combined with equatorial plasma diffusion along magnetic field lines to higher latitudes, creating a "daytime super-fountain" effect.

  18. Observations of interplanetary scintillation during the 1998 Whole Sun Month: a comparison between EISCAT, ORT and Nagoya data

    Directory of Open Access Journals (Sweden)

    P. J. Moran

    2000-09-01

    Full Text Available Observations of interplanetary scintillation (IPS allow accurate solar wind velocity measurements to be made at all heliographic latitudes and at a range of distances from the Sun. The data may be obtained with either single, double or multiple antennas, each requiring a different method of analysis. IPS data taken during the 1998 whole sun month (30th July-31st August 1998 by EISCAT, the ORT (Ooty Radio Telescope, India, and the Nagoya IPS system, Japan, allow the results of individual methods of analysis to be compared. Good agreement is found between the velocity measurements using each method, and when combined an improved understanding of the structure of the solar wind can be obtained.Key words: Interplanetary physics (solar wind plasma; sources of the solar wind - Solar physics, astrophysics and astronomy (instruments and techniques

  19. Connection between the interplanetary medium and pulsations of the geomagnetic field with periods 1-600 s

    International Nuclear Information System (INIS)

    Hollo, L.

    1985-01-01

    The connection between the activity of the geomagnetic pulsations with periods of 1-600 s and some parameters of the interplanetary medium (magnitude and direction of the interplanetary magnetic fiels, IMF, and solar wind velocity) was studied on the basis of the records from the years 1971-1973 of the Nagycenk Observatory, Hungary. The activity of the pulsations with periods less than 30 s increases with increasing IMF magnitude as described by the hyperbolic connection between the two quantities. The maximum activity was found for periods below 30 s at a cone angle of 30 deg, while the maximum for longer periods lies at 0 deg. The increase of the amplitudes due to increasing solar wind velocity is the strongest for periods of 15-30 s. (author)

  20. Solar discrepancies: Mars exploration and the curious problem of inter-planetary time

    Science.gov (United States)

    Mirmalek, Zara Lenora

    The inter-planetary work system for the NASA's Mars Exploration Rovers (MER) mission entailed coordinating work between two corporally diverse workgroups, human beings and solar-powered robots, and between two planets with asynchronous axial rotations. The rotation of Mars takes approximately 24 hours and 40 minutes while for Earth the duration is 24 hours, a differential that was synchronized on Earth by setting a clock forward forty minutes every day. The hours of the day during which the solar-powered rovers were operational constituted the central consideration in the relationship between time and work around which the schedule of MER science operations were organized. And, the operational hours for the rovers were precarious for at least two reasons: on the one hand, the possibility of a sudden and inexplicable malfunction was always present; on the other, the rovers were powered by solar-charged batteries that could simply (and would eventually) fail. Thus, the timetable for the inter-planetary work system was scheduled according to the daily cycle of the sun on Mars and a version of clock time called Mars time was used to keep track of the movement of the sun on Mars. While the MER mission was a success, it does not necessarily follow that all aspects of mission operations were successful. One of the central problems that plagued the organization of mission operations was precisely this construct called "Mars time" even while it appeared that the use of Mars time was unproblematic and central to the success of the mission. In this dissertation, Zara Mirmalek looks at the construction of Mars time as a tool and as a social process. Of particular interest are the consequences of certain (ostensibly foundational) assumptions about the relationship between clock time and the conduct of work that contributed to making the relationship between Mars time and work on Earth appear operational. Drawing on specific examples of breakdowns of Mars time as a support

  1. Finite-thrust optimization of interplanetary transfers of space vehicle with bimodal nuclear thermal propulsion

    Science.gov (United States)

    Kharytonov, Oleksii M.; Kiforenko, Boris M.

    2011-08-01

    The nuclear thermal rocket (NTR) propulsion is one of the leading promising technologies for primary space propulsion for manned exploration of the solar system due to its high specific impulse capability and sufficiently high thrust-to-weight ratio. Another benefit of NTR is its possible bimodal design, when nuclear reactor is used for generation of a jet thrust in a high-thrust mode and (with an appropriate power conversion system) as a source of electric power to supply the payload and the electric engines in a low-thrust mode. The model of the NTR thrust control was developed considering high-thrust NTR as a propulsion system of limited power and exhaust velocity. For the proposed model the control of the thrust value is accomplished by the regulation of reactor thermal power and propellant mass flow rate. The problem of joint optimization of the combination of high- and low-thrust arcs and the parameters of bimodal NTR (BNTR) propulsion system is considered for the interplanetary transfers. The interplanetary trajectory of the space vehicle is formed by the high-thrust NTR burns, which define planet-centric maneuvers and by the low-thrust heliocentric arcs where the nuclear electric propulsion (NEP) is used. The high-thrust arcs are analyzed using finite-thrust approach. The motion of the corresponding dynamical system is realized in three phase spaces concerning the departure planet-centric maneuver by means of high-thrust NTR propulsion, the low-thrust NEP heliocentric maneuver and the approach high-thrust NTR planet-centric maneuver. The phase coordinates are related at the time instants of the change of the phase spaces due to the relations between the space vehicle masses. The optimal control analysis is performed using Pontryagin's maximum principle. The numerical results are analyzed for Earth-Mars "sprint" transfer. The optimal values of the parameters that define the masses of NTR and NEP subsystems have been evaluated. It is shown that the low

  2. The Swedish Interplanetary Society (1950-1969) and the formation of IAF and IAA

    Science.gov (United States)

    Ingemar Skoog, A.

    2011-06-01

    With a growing interest for rocket technology and space travel after WW II a number of new "space societies" were formed in the period 1948-1951 in addition to the ones already existing in Germany, the UK and the US since before WW II. Soon came the need for a common international platform for exchange of information and experience, and the concept of an international federation of astronautical societies emerged. Sweden was one of the 8 countries to sign the original declaration to create an International Astronautical Federation on October 2, 1950 in Paris at the 1st International Astronautical Congress. The Swedish Society for Space Research (Svenska Sällskapet för Rymdforskning) was formed a few days after the historical event in Paris. The name was soon to be changed to the Swedish Interplanetary Society (Svenska Interplanetariska Sällskapet, SIS). Sweden was one of the 10 countries to sign the IAF foundation in 1951 in London and in the following year the first Constitution of IAF in Stuttgart. The SIS quickly grow to a membership of several hundred persons and its membership in IAF promoted an intensive exchange of journals, and the annual participation at the IAC gave growth to start study projects on spacecraft and sounding rockets, and the publication of astronautical journals in Swedish. In 1957 the first Swede was elected vice-president of IAF. Not too long after the IAF foundation the idea of an international body of distinguished individuals emerged, in addition to the body of "member societies" (IAF). Upon the initiative of Theodor von Karman, Eugen Sänger and Andrew Haley the IAF council approval of an International Academy of Astronautical was given on August 15, 1960 during the 11th IAC in Stockholm. This IAC in Stockholm gave a large publicity to space research and astronautics in Sweden, and put the activities of the SIS in the focus of the general public. This paper presents the Swedish involvement in the foundation of IAF and IAA. It also

  3. Navigation: Bat orientation using Earth's magnetic field

    DEFF Research Database (Denmark)

    Holland, Richard A.; Thorup, Kasper; Vonhof, Maarten J.

    2006-01-01

    Bats famously orientate at night by echolocation 1 , but this works over only a short range, and little is known about how they navigate over longer distances 2 . Here we show that the homing behaviour of Eptesicus fuscus, known as the big brown bat, can be altered by artificially shifting...... the Earth's magnetic field, indicating that these bats rely on a magnetic compass to return to their home roost. This finding adds to the impressive array of sensory abilities possessed by this animal for navigation in the dark....

  4. Lucy: Navigating a Jupiter Trojan Tour

    Science.gov (United States)

    Stanbridge, Dale; Williams, Ken; Williams, Bobby; Jackman, Coralie; Weaver, Hal; Berry, Kevin; Sutter, Brian; Englander, Jacob

    2017-01-01

    In January 2017, NASA selected the Lucy mission to explore six Jupiter Trojan asteroids. These six bodies, remnants of the primordial material that formed the outer planets, were captured in the Sun-Jupiter L4 and L5 Lagrangian regions early in the solar system formation. These particular bodies were chosen because of their diverse spectral properties and the chance to observe up close for the first time two orbiting approximately equal mass binaries, Patroclus and Menoetius. KinetX, Inc. is the primary navigation supplier for the Lucy mission. This paper describes preliminary navigation analyses of the approach phase for each Trojan encounter.

  5. Computer navigation versus fluoroscopy-guided navigation for thoracic pedicle screw placement: a meta-analysis.

    Science.gov (United States)

    Meng, Xiao-Tong; Guan, Xiao-Fei; Zhang, Hai-Long; He, Shi-Sheng

    2016-07-01

    Although application of intraoperative computer navigation technique had been integrated into placement of pedicle screws (PSs) in thoracic fusion for years, its security and practicability remain controversial. The aim of this study is to evaluate the accuracy, the operative time consumption, the amount of intraoperative blood loss, time of pedicle insertion and the incidence of complications of thoracic pedicle screw placement in patients with thoracic diseases such as scoliosis and kyphosis. Pubmed, Web of Knowledge, and Google scholar were searched to identify comparative studies of thoracic pedicle screw placement between intraoperative computer navigation and fluoroscopy-guided navigation. Outcomes of malposition rate, operative time consumption, insertion time, intraoperative blood loss, and the incidence of complications are evaluated. Fourteen articles including 1723 patients and 9019 PSs were identified matching inclusion criteria. The malposition rate was lower (RR: 0.33, 95 % CI: 0.28-0.38, P fluoroscopy-guided navigation group; the operative time was significantly longer [weighted mean difference (WMD) = 23.66, 95 % CI: 14.74-32.57, P fluoroscopy-guided navigation group. The time of insertion was shorter (WMD = -1.88, 95 % CI: -2.25- -1.52, P fluoroscopy-guided navigation group. The incidence of complications was lower (RR = 0. 23, 95 % CI: 0.12-0.46, P fluoroscopy-guided navigation.

  6. The Interplanetary Network Supplement to the Fermi GBM Catalog - An AO-2 and AO-3 Guest Investigator Project

    Science.gov (United States)

    Hurley, K.; Briggs, M.; Connaughton, V.; Meegan, C.; von Kienlin, A.; Rau, A.; Zhang, X.; Golenetskii, S.; Aptekar, R.; Mazets, E.; hide

    2012-01-01

    In the first two years of operation of the Fermi GBM, the 9-spacecraft Interplanetary Network (IPN) detected 158 GBM bursts with one or two distant spacecraft, and triangulated them to annuli or error boxes. Combining the IPN and GBM localizations leads to error boxes which are up to 4 orders of magnitude smaller than those of the GBM alone. These localizations comprise the IPN supplement to the GBM catalog, and they support a wide range of scientific investigations.

  7. Using ACE Observations of Interplanetary Particles and Magnetic Fields as Possible Contributors to Variations Observed at Van Allen Probes during Major events in 2013

    Science.gov (United States)

    Armstrong, T. P.; Manweiler, J. W.; Gerrard, A. J.; Gkioulidou, M.; Lanzerotti, L. J.; Patterson, J. D.

    2013-12-01

    Observations from ACE EPAM including energy spectra of protons, helium, and oxygen will be prepared for coordinated use in estimating the direct and indirect access of energetic particles to inner and outer geomagnetic trapping zones. Complete temporal coverage from ACE at 12 seconds, 5 minutes, 17 minutes, hourly and daily cadences will be used to catalog interplanetary events arriving at Earth including interplanetary magnetic field sector boundaries, interplanetary shocks, and interplanetary coronal mass ejections, ICMEs. The first 6 months of 2013 have included both highly disturbed times, March 17 and May 22, and extended quiet periods of little or no variations. Among the specific questions that ACE and Van Allen Probes coordinated observations may aid in resolving are: 1. How much, if any, direct capture of interplanetary energetic particles occurs and what conditions account for it? 2. How much influence do interplanetary field and particle variations have on energization and/or loss of geomagnetically trapped populations? The poster will also present important links and describe methods and important details of access to numerically expressed ACE EPAM and Van Allen Probes RBSPICE observations that can be flexibly and easily accessed via the internet for student and senior researcher use.

  8. Navigation Problems in Blind-to-Blind Pedestrians Tele-assistance Navigation

    OpenAIRE

    Balata , Jan; Mikovec , Zdenek; Maly , Ivo

    2015-01-01

    International audience; We raise a question whether it is possible to build a large-scale navigation system for blind pedestrians where a blind person navigates another blind person remotely by mobile phone. We have conducted an experiment, in which we observed blind people navigating each other in a city center in 19 sessions. We focused on problems in the navigator’s attempts to direct the traveler to the destination. We observed 96 problems in total, classified them on the basis of the typ...

  9. From the sun's corona to the polar cusp aurora above Svalbard. Interplanetary and terrestrial effects of a coronal transient

    International Nuclear Information System (INIS)

    Sandholt, P.E.

    1986-08-01

    The report presents a study of the flare-related coronal transient of Nov. 27, 1979, with the resulting interplanetary (IP) shock, and the associated auroral and magnetic effects that were observed from the ground 72 hours after the initial coronal brightening. The observed disturbance of the interplanetary magnetic field (IMF) resulting from the coronal mass ejection is discussed in relation to a model discription of flare-related perturbations of the solar current sheet. The power transfer from the solar wind to the magnetosphere did not rise above the treshold value for magnetospheric strom triggering in this case. thus, the IP shock was not followed by a major storm. However, distinct signatures related to the IP disturbance were observed in the polar cusp aurorae above Svaldbard and in the local magnetic field. The dynamical behaviour of the cusp aurora is discussed in relation to different models of plasma transfer across the dayside magnetopause, from the shocked solar wind to the magnetosphere. A detailed analysis of the available information from interplanetary space and the ground indicates that the main auroral dynamics observed in this case are related to localized, impulsive plasma injections associated with flux transfer events

  10. CAWSES November 7-8, 2004, Superstorm: Complex Solar and Interplanetary Features in the Post-Solar Maximum Phase

    Science.gov (United States)

    Tsurutani, Bruce T.; Echer, Ezequiel; Guarnieri, Fernando L.; Kozyra, J. U.

    2008-01-01

    The complex interplanetary structures during 7 to 8 Nov 2004 are analyzed to identify their properties as well as resultant geomagnetic effects and the solar origins. Three fast forward shocks, three directional discontinuities and two reverse waves were detected and analyzed in detail. The three fast forward shocks 'pump' up the interplanetary magnetic field from a value of approx.4 nT to 44 nT. However, the fields after the shocks were northward, and magnetic storms did not result. The three ram pressure increases were associated with major sudden impulses (SI + s) at Earth. A magnetic cloud followed the third forward shock and the southward Bz associated with the latter was responsible for the superstorm. Two reverse waves were detected, one at the edge and one near the center of the magnetic cloud (MC). It is suspected that these 'waves' were once reverse shocks which were becoming evanescent when they propagated into the low plasma beta MC. The second reverse wave caused a decrease in the southward component of the IMF and initiated the storm recovery phase. It is determined that flares located at large longitudinal distances from the subsolar point were the most likely causes of the first two shocks without associated magnetic clouds. It is thus unlikely that the shocks were 'blast waves' or that magnetic reconnection eroded away the two associated MCs. This interplanetary/solar event is an example of the extremely complex magnetic storms which can occur in the post-solar maximum phase.

  11. Interplanetary Magnetic Field Power Spectrum Variations in the Inner Heliosphere: A Wind and MESSENGER Study

    Science.gov (United States)

    Szabo, Adam; Koval, A.

    2011-01-01

    The newly reprocessed high time resolution (11/22 vectors/sec) Wind mission interplanetary magnetic field data and the similar observations made by the MESSENGER spacecraft in the inner heliosphere affords an opportunity to compare magnetic field power spectral density variations as a function of radial distance from the Sun under different solar wind conditions. In the reprocessed Wind Magnetic Field Investigation (MFI) data, the spin tone and its harmonics are greatly reduced that allows the meaningful fitting of power spectra to the approx.2 Hz limit above which digitization noise becomes apparent. The powe'r spectral density is computed and the spectral index is fitted for the MHD and ion inertial regime separately along with the break point between the two for various solar wind conditions. Wind and MESSENGER magnetic fluctuations are compared for times when the two spacecraft are close to radial and Parker field alignment. The functional dependence of the ion inertial spectral index and break point on solar wind plasma and magnetic field conditions will be discussed.

  12. Assemblage of Presolar Materials and Early Solar System Condensates in Chondritic Porous Interplanetary Dust Particles

    Science.gov (United States)

    Nguyen, A. N.; Nakamura-Messenger, K.; Messenger, S.; Keller, L. P.; Kloeck, W.

    2015-01-01

    Anhydrous chondritic porous inter-planetary dust particles (CP IDPs) contain an assortment of highly primitive solar system components, molecular cloud matter, and presolar grains. These IDPs have largely escaped parent body processing that has affected meteorites, advocating cometary origins. Though the stardust abundance in CP IDPs is generally greater than in primitive meteorites, it can vary widely among individual CP IDPs. The average abundance of silicate stardust among isotopically primitive IDPs is approx. 375 ppm while some have extreme abundances up to approx. 1.5%. H and N isotopic anomalies are common in CP IDPs and the carrier of these anomalies has been traced to organic matter that has experienced chemical reactions in cold molecular clouds or the outer protosolar disk. Significant variations in these anomalies may reflect different degrees of nebular processing. Refractory inclusions are commonly observed in carbonaceous chondrites. These inclusions are among the first solar system condensates and display 16O-rich isotopic compositions. Refractory grains have also been observed in the comet 81P/Wild-2 samples re-turned from the Stardust Mission and in CP IDPs, but they occur with much less frequency. Here we conduct coordinated mineralogical and isotopic analyses of CP IDPs that were characterized for their bulk chemistry by to study the distribution of primitive components and the degree of nebular alteration incurred.

  13. Interplanetary shock transmitted into the Earth's magnetosheath: Cluster and Double Star observations

    Directory of Open Access Journals (Sweden)

    G. Pallocchia

    2010-05-01

    Full Text Available On day 7 May 2005, the plasma instruments on board Double Star TC1 and Cluster SC3 spacecraft register inside the magnetosheath, at 19:15:12 and 19:16:20 UT, respectively, a strong pressure pulse due to the impact of an interplanetary shock wave (IS on the terrestrial bow shock. The analysis of this event provides clear and quantitative evidences confirming and strengthening some results given by past simulations and observational studies. In fact, here we show that the transmitted shock is slowed down with respect to the incident IS (in the Earth's reference frame and that, besides the transmitted shock, the IS – bow shock interaction generates a second discontinuity. Moreover, supported also by a special set three-dimensional magnetohydrodynamic simulation, we discuss, as further effects of the interaction of the IS with the magnetosphere, other two interesting aspects of the present event, that is: the TC1 double crossing of the bow shock (observed few minutes after the impact of the IS and the presence, only in the SC3 data, of a third discontinuity produced inside the magnetosheath.

  14. High Precision Oxygen Three Isotope Analysis of Wild-2 Particles and Anhydrous Chondritic Interplanetary Dust Particles

    Science.gov (United States)

    Nakashima, D.; Ushikubo, T.; Zolensky, Michael E.; Weisberg, M. K.; Joswiak, D. J.; Brownlee, D. E.; Matrajt, G.; Kita, N. T.

    2011-01-01

    One of the most important discoveries from comet Wild-2 samples was observation of crystalline silicate particles that resemble chondrules and CAIs in carbonaceous chondrites. Previous oxygen isotope analyses of crystalline silicate terminal particles showed heterogeneous oxygen isotope ratios with delta(sup 18)O to approx. delta(sup 17)O down to -50% in the CAI-like particle Inti, a relict olivine grain in Gozen-sama, and an olivine particle. However, many Wild-2 particles as well as ferromagnesian silicates in anhydrous interplanetary dust particles (IDPs) showed Delta(sup 17)O values that cluster around -2%. In carbonaceous chondrites, chondrules seem to show two major isotope reservoirs with Delta(sup 17)O values at -5% and -2%. It was suggested that the Delta(sup 17)O = -2% is the common oxygen isotope reservoir for carbonaceous chondrite chondrules and cometary dust, from the outer asteroid belt to the Kuiper belt region. However, a larger dataset with high precision isotope analyses (+/-1-2%) is still needed to resolve the similarities or distinctions among Wild-2 particles, IDPs and chondrules in meteorites. We have made signifi-cant efforts to establish routine analyses of small particles (isotope analyses of Wild-2 particles and anhydrous chondritic IDPs, and discuss the relationship between the cometary dust and carbonaceous chondrite chondrules.

  15. Analytical electron microscopy of fine-grained phases in primitive interplanetary dust particles and carbonaceous chondrites

    Science.gov (United States)

    Mackinnon, Ian D. R.; Rietmeijer, Frans J. M.; Mckay, David S.

    1987-01-01

    In order to describe the total mineralogical diversity within primitive extraterrestrial materials, individual interplanetary dust particles (IDPs) collected from the stratosphere as part of the JSC Cosmic Dust Curatorial Program were analyzed using a variety of AEM techniques. Identification of over 250 individual grains within one chondritic porous (CP) IDP shows that most phases could be formed by low temperature processes and that heating of the IDP during atmospheric entry is minimal and less than 600 C. In a review of the mineralogy of IDPs, it was suggested that the occurrence of other silicates such as enstatite whiskers is consistent with the formation in an early turbulent period of the solar nebula. Experimental confirmation of fundamental chemical and physical processes in a stellar environment, such as vapor phase condensation, nucleation, and growth by annealing, is an important aspect of astrophysical models for the evolution of the Solar System. A detailed comparison of chondritic IDP and carbonaceous chondrite mineralogies shows significant differences between the types of silicate minerals as well as the predominant oxides.

  16. Linear response of field-aligned currents to the interplanetary electric field

    Science.gov (United States)

    Weimer, D. R.; Edwards, T. R.; Olsen, Nils

    2017-08-01

    Many studies that have shown that the ionospheric, polar cap electric potentials (PCEPs) exhibit a "saturation" behavior in response to the level of the driving by the solar wind. As the magnitudes of the interplanetary magnetic field (IMF) and electric field (IEF) increase, the PCEP response is linear at low driving levels, followed with a rollover to a more constant level. While there are several different theoretical explanations for this behavior, so far, no direct observational evidence has existed to confirm any particular model. In most models of this saturation, the interaction of the field-aligned currents (FACs) with the solar wind/magnetosphere/ionosphere system has a role. As the FACs are more difficult to measure, their behavior in response to the level of the IEF has not been investigated as thoroughly. In order to resolve the question of whether or not the FAC also exhibit saturation, we have processed the magnetic field measurements from the Ørsted, CHAMP, and Swarm missions, spanning more than a decade. As the amount of current in each region needs to be known, a new technique is used to separate and sum the current by region, widely known as R0, R1, and R2. These totals are found separately for the dawnside and duskside. Results indicate that the total FAC has a response to the IEF that is highly linear, continuing to increase well beyond the level at which the electric potentials saturate. The currents within each region have similar behavior.

  17. An analysis of interplanetary space radiation exposure for various solar cycles

    International Nuclear Information System (INIS)

    Badhwar, G.D.; O'Neill, P.M.; Cucinotta, F.A.

    1994-01-01

    The radiation dose received by crew members in interplanetary space is influenced by the stage of the solar cycle. Using the recently developed models of the galactic cosmic radiation (GCR) environment and the energy-dependent radiation transport code, we have calculated the dose at 0 and 5 cm water depth; using a computerized anatomical man (CAM) model, we have calculated the skin, eye and blood-forming organ (BFO) doses as a function of aluminum shielding for various solar minima and maxima between 1954 and 1989. These results show that the equivalent dose is within about 15% of the mean for the various solar minima (maxima). The maximum variation between solar minimum and maximum equivalent dose is about a factor of three. We have extended these calculations for the 1967-1977 solar minimum to five practical shielding geometries: Apollo Command Module, the least and most heavily shielded locations in the U.S. space shuttle mid-deck, center of the proposed Space Station Freedom cluster and sleeping compartment of the Skylab. These calculations, using the quality factor of ICRP 60, show that the average CAM BFO equivalent dose is 0.46 Sv/year. Based on an approach that takes fragmentation into account, we estimate a calculation uncertainty of 15% if the uncertainty in the quality factor is neglected. 25 refs., 11 figs., 1 tab

  18. Some low-altitude cusp dependencies on the interplanetary magnetic field

    International Nuclear Information System (INIS)

    Newell, P.T.; Meng, C.; Sibeck, D.G.; Lepping, R.

    1989-01-01

    Although it has become well established that the low-altitude polar cusp moves equatorward during intervals of southward interplanetary magnetic field (IMF B z y negative (positive) in the northern (southern) hemisphere and postnoon for B y positive (negative) in the northern (southern) hemisphere. The B y induced shift is much more pronounced for southward than for northward B z , a result that appears to be consistent with elementary considerations from, for example, the antiparallel merging model. No interhemispherical latitudinal differences in cusp positions were found that could be attributed to the IMF B x component. As expected, the cusp latitudinal position correlated reasonably well (0.70) with B z when the IMF had a southward component; the previously much less investigated correlation for B z northward proved to be only 0.18, suggestive of a half-wave rectifier effect. The ratio of cusp ion number flux precipitation for B z southward to that for B z northward was 1.75±0.12. The statistical local time (full) width of the cusp proper was found to be 2.1 hours for B z northward and 2.8 hours for B z southward. copyright American Geophysical Union 1989

  19. Interplanetary Coronal Mass Ejection effects on thermospheric density as inferred from International Space Station orbital data

    Science.gov (United States)

    Mendaza, T.; Blanco-Ávalos, J. J.; Martín-Torres, J.

    2017-11-01

    The solar activity induces long term and short term periodical variations in the dynamics and composition of Earth's atmosphere. The Sun also shows non periodical (i.e., impulsive) activity that reaches the planets orbiting around it. In particular, Interplanetary Coronal Mass Ejections (ICMEs) reach Earth and interact with its magnetosphere and upper neutral atmosphere. Nevertheless, the interaction with the upper atmosphere is not well characterized because of the absence of regular and dedicated in situ measurements at high altitudes; thus, current descriptions of the thermosphere are based on semi empirical models. In this paper, we present the total neutral mass densities of the thermosphere retrieved from the orbital data of the International Space Station (ISS) using the General Perturbation Method, and we applied these densities to routinely compiled trajectories of the ISS in low Earth orbit (LEO). These data are explicitly independent of any atmospheric model. Our density values are consistent with atmospheric models, which demonstrates that our method is reliable for the inference of thermospheric density. We have inferred the thermospheric total neutral density response to impulsive solar activity forcing from 2001 to the end of 2006 and determined how solar events affect this response. Our results reveal that the ISS orbital parameters can be used to infer the thermospheric density and analyze solar effects on the thermosphere.

  20. Magnetic Flux Circulation During Dawn-Dusk Oriented Interplanetary Magnetic Field

    Science.gov (United States)

    Mitchell, E. J.; Lopez, R. E.; Fok, M.-C.; Deng, Y.; Wiltberger, M.; Lyon, J.

    2010-01-01

    Magnetic flux circulation is a primary mode of energy transfer from the solar wind into the ionosphere and inner magnetosphere. For southward interplanetary magnetic field (IMF), magnetic flux circulation is described by the Dungey cycle (dayside merging, night side reconnection, and magnetospheric convection), and both the ionosphere and inner magnetosphere receive energy. For dawn-dusk oriented IMF, magnetic flux circulation is not well understood, and the inner magnetosphere does not receive energy. Several models have been suggested for possible reconnection patterns; the general pattern is: dayside merging; reconnection on the dayside or along the dawn/dusk regions; and, return flow on dayside only. These models are consistent with the lack of energy in the inner magnetosphere. We will present evidence that the Dungey cycle does not explain the energy transfer during dawn-dusk oriented IMF. We will also present evidence of how magnetic flux does circulate during dawn-dusk oriented IMF, specifically how the magnetic flux reconnects and circulates back.

  1. Low-latitude active longitudes on the Sun and in interplanetary space

    International Nuclear Information System (INIS)

    Bumba, V.; Hejna, L.

    1991-01-01

    Following a short review of the history of the development of the active longitude concept, several graphs are given of the longitudinal distribution of various low-latitude phenomena of solar activity published by various authors. The inclinations of the active longitudes found were calculated. A summary picture of all these inclinations demonstrates the concentration of such active longitudes into two main directions. Two values of synodic rotation: 26.77 days and 27.16 days, correspond to these two types of low-latitude active longitudes, rotating faster than Carrington's rotation. The summary graph of all active longitudes belonging to these two types shows that active longitudes of different activity phenomena and from different authors overlap to a relatively high degree and that they run at least through three eleven-year cycles. The first of these active longitudes moves around the whole Sun in about 45-55 rotations and the second one in about 200 Carrington's rotations. It is believed that both these low-latitude active longitudes have their reflections in the two main inclinations of the interplanetary magnetic field sector boundaries demonstrated by Svalgaard and Wilcox (1975), their synodic rotations being 26.84 days and 27.14 days. (author). 9 figs., 25 refs

  2. Virulence as a model for interplanetary and interstellar colonization - parasitism or mutualism?

    Science.gov (United States)

    Starling, Jonathan; Forgan, Duncan H.

    2014-01-01

    In the light of current scientific assessments of human-induced climate change, we investigate an experimental model to inform how resource-use strategies may influence interplanetary and interstellar colonization by intelligent civilizations. In doing so, we seek to provide an additional aspect for refining the famed Fermi Paradox. The model described is necessarily simplistic, and the intent is to simply obtain some general insights to inform and inspire additional models. We model the relationship between an intelligent civilization and its host planet as symbiotic, where the relationship between the symbiont and the host species (the civilization and the planet's ecology, respectively) determines the fitness and ultimate survival of both organisms. We perform a series of Monte Carlo Realization simulations, where civilizations pursue a variety of different relationships/strategies with their host planet, from mutualism to parasitism, and can consequently `infect' other planets/hosts. We find that parasitic civilizations are generally less effective at survival than mutualist civilizations, provided that interstellar colonization is inefficient (the maximum velocity of colonization/infection is low). However, as the colonization velocity is increased, the strategy of parasitism becomes more successful, until they dominate the `population'. This is in accordance with predictions based on island biogeography and r/K selection theory. While heavily assumption dependent, we contend that this provides a fertile approach for further application of insights from theoretical ecology for extraterrestrial colonization - while also potentially offering insights for understanding the human-Earth relationship and the potential for extraterrestrial human colonization.

  3. Simulated Prompt Acceleration of Multi-MeV Electrons by the 17 March 2015 Interplanetary Shock

    Science.gov (United States)

    Hudson, Mary; Jaynes, Allison; Kress, Brian; Li, Zhao; Patel, Maulik; Shen, Xiao-Chen; Thaller, Scott; Wiltberger, Michael; Wygant, John

    2017-10-01

    Prompt enhancement of relativistic electron flux at L = 3-5 has been reported from Van Allen Probes Relativistic Electron Proton Telescope (REPT) measurements associated with the 17 March 2015 interplanetary shock compression of the dayside magnetosphere. Acceleration by ˜1 MeV is inferred on less than a drift timescale as seen in prior shock compression events, which launch a magnetosonic azimuthal electric field impulse tailward. This impulse propagates from the dayside around the flanks accelerating electrons in drift resonance at the dusk flank. Such longitudinally localized acceleration events produce a drift echo signature which was seen at >1 MeV energy on both Van Allen Probe spacecraft, with sustained observations by Probe B outbound at L = 5 at 2100 MLT at the time of impulse arrival, measured by the Electric Fields and Waves instrument. MHD test particle simulations are presented which reproduce drift echo features observed in the REPT measurements at Probe B, including the energy and pitch angle dependence of drift echoes observed. While the flux enhancement was short lived for this event due to subsequent inward motion of the magnetopause, stronger events with larger electric field impulses, as observed in March 1991 and the Halloween 2003 storm, produce enhancements which can be quantified by the inward radial transport and energization determined by the induction electric field resulting from dayside compression.

  4. Are interplanetary magnetic clouds manifestations of coronal transients at 1 AU

    International Nuclear Information System (INIS)

    Wilson, R.M.; Hildner, E.

    1984-01-01

    Using proxy data for the occurrence of those mass ejections from the solar corona which are directed earthward, we investigate the association between the post-1970 interplanetary magnetic clouds of Klein and Burlaga (1982) and coronal mass ejections. The evidence linking magnetic clouds following shocks with coronal mass ejections is striking; six of nine clouds observed at Earth were preceded an appropriate time earlier by meter-wave type II radio bursts indicative of coronal shock waves and coronal mass ejections occurring near central meridian. During the selected control periods when no clouds were detected near Earth, the only type II bursts reported were associated with solar activity near the limbs. Where the proxy solar data to be sought are not so clearly suggested, that is, for clouds preceding interaction regions and clouds within cold magnetic enhancements, the evidence linking the clouds and coronal mass ejections is not as clear; proxy data usually suggest many candidate mass-ejection events for each cloud. Overall, the data are consistent with and support the hypothesis suggested by Klein and Burlaga that magnetic clouds observed with spacecraft at 1 AU are manifestations of solar coronal mass ejection transients. (orig.)

  5. Central polar cap convection response to short duration southward Interplanetary Magnetic Field

    Directory of Open Access Journals (Sweden)

    P. T. Jayachandran

    2000-08-01

    Full Text Available Central polar cap convection changes associated with southward turnings of the Interplanetary Magnetic Field (IMF are studied using a chain of Canadian Advanced Digital Ionosondes (CADI in the northern polar cap. A study of 32 short duration (~1 h southward IMF transition events found a three stage response: (1 initial response to a southward transition is near simultaneous for the entire polar cap; (2 the peak of the convection speed (attributed to the maximum merging electric field propagates poleward from the ionospheric footprint of the merging region; and (3 if the change in IMF is rapid enough, then a step in convection appears to start at the cusp and then propagates antisunward over the polar cap with the velocity of the maximum convection. On the nightside, a substorm onset is observed at about the time when the step increase in convection (associated with the rapid transition of IMF arrives at the polar cap boundary.Key words: Ionosphere (plasma convection; polar ionosphere - Magnetospheric physics (solar wind - magnetosphere interaction

  6. Central polar cap convection response to short duration southward Interplanetary Magnetic Field

    Directory of Open Access Journals (Sweden)

    P. T. Jayachandran

    Full Text Available Central polar cap convection changes associated with southward turnings of the Interplanetary Magnetic Field (IMF are studied using a chain of Canadian Advanced Digital Ionosondes (CADI in the northern polar cap. A study of 32 short duration (~1 h southward IMF transition events found a three stage response: (1 initial response to a southward transition is near simultaneous for the entire polar cap; (2 the peak of the convection speed (attributed to the maximum merging electric field propagates poleward from the ionospheric footprint of the merging region; and (3 if the change in IMF is rapid enough, then a step in convection appears to start at the cusp and then propagates antisunward over the polar cap with the velocity of the maximum convection. On the nightside, a substorm onset is observed at about the time when the step increase in convection (associated with the rapid transition of IMF arrives at the polar cap boundary.

    Key words: Ionosphere (plasma convection; polar ionosphere - Magnetospheric physics (solar wind - magnetosphere interaction

  7. INVESTIGATION OF PRIMORDIAL BLACK HOLE BURSTS USING INTERPLANETARY NETWORK GAMMA-RAY BURSTS

    Energy Technology Data Exchange (ETDEWEB)

    Ukwatta, T. N. [Director' s Postdoctoral Fellow, Space and Remote Sensing (ISR-2), Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Hurley, K. [University of California, Berkeley, Space Sciences Laboratory, 7 Gauss Way, Berkeley, CA 94720-7450 (United States); MacGibbon, J. H. [Department of Physics, University of North Florida, Jacksonville, FL 32224 (United States); Svinkin, D. S.; Aptekar, R. L.; Golenetskii, S. V.; Frederiks, D. D.; Pal' shin, V. D. [Ioffe Physical Technical Institute, St. Petersburg, 194021 (Russian Federation); Goldsten, J. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Boynton, W. [Department of Planetary Sciences, University of Arizona, Tucson, AZ 85721 (United States); Kozyrev, A. S. [Space Research Institute, 84/32, Profsoyuznaya, Moscow 117997 (Russian Federation); Rau, A.; Kienlin, A. von; Zhang, X. [Max-Planck-Institut für extraterrestrische Physik, Giessenbachstrasse, Postfach 1312, Garching, D-85748 (Germany); Connaughton, V. [University of Alabama in Huntsville, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805 (United States); Yamaoka, K. [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Sagamihara, Kanagawa 229-8558 (Japan); Ohno, M. [Department of Physics, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Ohmori, N. [Department of Applied Physics, University of Miyazaki, 1-1 Gakuen kibanadai-nishi, Miyazaki-shi, Miyazaki 889-2192 (Japan); Feroci, M. [INAF/IAPS-Roma, via Fosso del Cavaliere 100, I-00133, Roma (Italy); Frontera, F., E-mail: tilan@lanl.gov [Department of Physics and Earth Science, University of Ferrara, via Saragat 1, I-44122 Ferrara (Italy); and others

    2016-07-20

    The detection of a gamma-ray burst (GRB) in the solar neighborhood would have very important implications for GRB phenomenology. The leading theories for cosmological GRBs would not be able to explain such events. The final bursts of evaporating primordial black holes (PBHs), however, would be a natural explanation for local GRBs. We present a novel technique that can constrain the distance to GRBs using detections from widely separated, non-imaging spacecraft. This method can determine the actual distance to the burst if it is local. We applied this method to constrain distances to a sample of 36 short-duration GRBs detected by the Interplanetary Network (IPN) that show observational properties that are expected from PBH evaporations. These bursts have minimum possible distances in the 10{sup 13}–10{sup 18} cm (7–10{sup 5} au) range, which are consistent with the expected PBH energetics and with a possible origin in the solar neighborhood, although none of the bursts can be unambiguously demonstrated to be local. Assuming that these bursts are real PBH events, we estimate lower limits on the PBH burst evaporation rate in the solar neighborhood.

  8. STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

    International Nuclear Information System (INIS)

    Zuo, Pingbing; Feng, Xueshang; Wang, Yi; Xie, Yanqiong; Xu, Xiaojun

    2015-01-01

    In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector

  9. COMPOSITION STRUCTURE OF INTERPLANETARY CORONAL MASS EJECTIONS FROM MULTISPACECRAFT OBSERVATIONS, MODELING, AND COMPARISON WITH NUMERICAL SIMULATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Reinard, Alysha A. [University of Colorado/Cooperative Institute for Research in Environmental Sciences and National Oceanic and Atmospheric Administration/Space Weather Prediction Center, Boulder, CO 80505 (United States); Lynch, Benjamin J. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Mulligan, Tamitha, E-mail: alysha.reinard@noaa.gov, E-mail: blynch@ssl.berkeley.edu, E-mail: tamitha.mulligan@aero.org [Space Sciences Department, Aerospace Corporation, Los Angeles, CA 90009 (United States)

    2012-12-20

    We present an analysis of the ionic composition of iron for two interplanetary coronal mass ejections (ICMEs) observed on 2007 May 21-23 by the ACE and STEREO spacecraft in the context of the magnetic structure of the ejecta flux rope, sheath region, and surrounding solar wind flow. This analysis is made possible due to recent advances in multispacecraft data interpolation, reconstruction, and visualization as well as results from recent modeling of ionic charge states in MHD simulations of magnetic breakout and flux cancellation coronal mass ejection (CME) initiation. We use these advances to interpret specific features of the ICME plasma composition resulting from the magnetic topology and evolution of the CME. We find that, in both the data and our MHD simulations, the flux ropes centers are relatively cool, while charge state enhancements surround and trail the flux ropes. The magnetic orientations of the ICMEs are suggestive of magnetic breakout-like reconnection during the eruption process, which could explain the spatial location of the observed iron enhancements just outside the traditional flux rope magnetic signatures and between the two ICMEs. Detailed comparisons between the simulations and data were more complicated, but a sharp increase in high iron charge states in the ACE and STEREO-A data during the second flux rope corresponds well to similar features in the flux cancellation results. We discuss the prospects of this integrated in situ data analysis and modeling approach to advancing our understanding of the unified CME-to-ICME evolution.

  10. An Iterative Interplanetary Scintillation (IPS) Analysis Using Time-dependent 3-D MHD Models as Kernels

    Science.gov (United States)

    Jackson, B. V.; Yu, H. S.; Hick, P. P.; Buffington, A.; Odstrcil, D.; Kim, T. K.; Pogorelov, N. V.; Tokumaru, M.; Bisi, M. M.; Kim, J.; Yun, J.

    2017-12-01

    The University of California, San Diego has developed an iterative remote-sensing time-dependent three-dimensional (3-D) reconstruction technique which provides volumetric maps of density, velocity, and magnetic field. We have applied this technique in near real time for over 15 years with a kinematic model approximation to fit data from ground-based interplanetary scintillation (IPS) observations. Our modeling concept extends volumetric data from an inner boundary placed above the Alfvén surface out to the inner heliosphere. We now use this technique to drive 3-D MHD models at their inner boundary and generate output 3-D data files that are fit to remotely-sensed observations (in this case IPS observations), and iterated. These analyses are also iteratively fit to in-situ spacecraft measurements near Earth. To facilitate this process, we have developed a traceback from input 3-D MHD volumes to yield an updated boundary in density, temperature, and velocity, which also includes magnetic-field components. Here we will show examples of this analysis using the ENLIL 3D-MHD and the University of Alabama Multi-Scale Fluid-Kinetic Simulation Suite (MS-FLUKSS) heliospheric codes. These examples help refine poorly-known 3-D MHD variables (i.e., density, temperature), and parameters (gamma) by fitting heliospheric remotely-sensed data between the region near the solar surface and in-situ measurements near Earth.

  11. Analytical electron microscopy of fine-grained phases in primitive interplanetary dust particles and carbonaceous chondrites

    International Nuclear Information System (INIS)

    Mackinnon, I.D.R.; Rietmeijer, F.J.M.; Mckay, D.S.

    1987-01-01

    In order to describe the total mineralogical diversity within primitive extraterrestrial materials, individual interplanetary dust particles (IDPs) collected from the stratosphere as part of the JSC Cosmic Dust Curatorial Program were analyzed using a variety of AEM techniques. Identification of over 250 individual grains within one chondritic porous (CP) IDP shows that most phases could be formed by low temperature processes and that heating of the IDP during atmospheric entry is minimal and less than 600 C. In a review of the mineralogy of IDPs, it was suggested that the occurrence of other silicates such as enstatite whiskers is consistent with the formation in an early turbulent period of the solar nebula. Experimental confirmation of fundamental chemical and physical processes in a stellar environment, such as vapor phase condensation, nucleation, and growth by annealing, is an important aspect of astrophysical models for the evolution of the Solar System. A detailed comparison of chondritic IDP and carbonaceous chondrite mineralogies shows significant differences between the types of silicate minerals as well as the predominant oxides

  12. A Database of Interplanetary and Interstellar Dust Detected by the Wind Spacecraft

    Science.gov (United States)

    Malaspina, David M.; Wilson, Lynn B., III

    2016-01-01

    It was recently discovered that the WAVES instrument on the Wind spacecraft has been detecting, in situ, interplanetary and interstellar dust of approximately 1 micron radius for the past 22 years. These data have the potential to enable advances in the study of cosmic dust and dust-plasma coupling within the heliosphere due to several unique properties: the Wind dust database spans two full solar cycles; it contains over 107,000 dust detections; it contains information about dust grain direction of motion; it contains data exclusively from the space environment within 350 Earth radii of Earth; and it overlaps by 12 years with the Ulysses dust database. Further, changes to the WAVES antenna response and the plasma environment traversed by Wind over the lifetime of the Wind mission create an opportunity for these data to inform investigations of the physics governing the coupling of dust impacts on spacecraft surfaces to electric field antennas. A Wind dust database has been created to make the Wind dust data easily accessible to the heliophysics community and other researchers. This work describes the motivation, methodology, contents, and accessibility of the Wind dust database.

  13. Neurosurgical robotic arm drilling navigation system.

    Science.gov (United States)

    Lin, Chung-Chih; Lin, Hsin-Cheng; Lee, Wen-Yo; Lee, Shih-Tseng; Wu, Chieh-Tsai

    2017-09-01

    The aim of this work was to develop a neurosurgical robotic arm drilling navigation system that provides assistance throughout the complete bone drilling process. The system comprised neurosurgical robotic arm navigation combining robotic and surgical navigation, 3D medical imaging based surgical planning that could identify lesion location and plan the surgical path on 3D images, and automatic bone drilling control that would stop drilling when the bone was to be drilled-through. Three kinds of experiment were designed. The average positioning error deduced from 3D images of the robotic arm was 0.502 ± 0.069 mm. The correlation between automatically and manually planned paths was 0.975. The average distance error between automatically planned paths and risky zones was 0.279 ± 0.401 mm. The drilling auto-stopping algorithm had 0.00% unstopped cases (26.32% in control group 1) and 70.53% non-drilled-through cases (8.42% and 4.21% in control groups 1 and 2). The system may be useful for neurosurgical robotic arm drilling navigation. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Global Navigation Satellite System and Augmentation

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 22; Issue 12. Global Navigation Satellite System and Augmentation ... Global availability of signal and continuous service hasmade GNSS technology popular with a large number of users.This article covers various aspects of GNSS/GPS like architecture ...

  15. 77 FR 67658 - Navigation Safety Advisory Council

    Science.gov (United States)

    2012-11-13

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard [Docket No. USCG-2012-0212] Navigation Safety Advisory.../en/hotels/florida/embassy-suites-tampa-downtown-convention-center-TPAESES/index.html . For... possible. To facilitate public participation, we are inviting public comment on the issues to be considered...

  16. The Navigation Metaphor in Security Economics

    NARCIS (Netherlands)

    Pieters, W.; Barendse, Jeroen; Ford, Margaret; Heath, Claude P R; Probst, Christian W.; Verbij, Ruud

    2016-01-01

    The navigation metaphor for cybersecurity merges security architecture models and security economics. By identifying the most efficient routes for gaining access to assets from an attacker's viewpoint, an organization can optimize its defenses along these routes. The well-understood concept of

  17. The navigation metaphor in security economics

    NARCIS (Netherlands)

    Pieters, Wolter; Barendse, Jeroen; Ford, Margaret; Heath, Claude P.R.; Probst, Christian W.; Verbij, Ruud

    2016-01-01

    The navigation metaphor for cybersecurity merges security architecture models and security economics. By identifying the most efficient routes for gaining access to assets from an attacker's viewpoint, an organization can optimize its defenses along these routes. The well-understood concept of

  18. Autonomous Rule Based Robot Navigation In Orchards

    DEFF Research Database (Denmark)

    Andersen, Jens Christian; Ravn, Ole; Andersen, Nils Axel

    2010-01-01

    Orchard navigation using sensor-based localization and exible mission management facilitates successful missions independent of the Global Positioning System (GPS). This is especially important while driving between tight tree rows where the GPS coverage is poor. This paper suggests localization ...

  19. A simple dead-reckoning navigational system

    Science.gov (United States)

    Walls, B. F.; Mastin, W. C.; Broussard, P., Jr.

    1972-01-01

    Simple navigation system is designed for vehicles operating in remote locations where it is not feasible to transport extensive equipment. System consists of four main components: directional gyrocompass to establish inertial direction; odometer to measure distance; signal processor to combine measured distance and direction; and sun compass to determine initial direction.

  20. Requirements for e-Navigation Architectures

    Directory of Open Access Journals (Sweden)

    Axel Hahn

    2016-12-01

    Full Text Available Technology is changing the way of navigation. New technologies for communication and navigation can be found on virtually every vessel. System architectures define structure and cooperation of components and subsystems. IMO, IALA, costal authorities, technology provider and many more actually propose new architectures for e-Navigation. This paper looks at other transportation domains and technical as normative requirements for e-Navigation architectures. With the aim of identifying possible synergies in the research, development, certification and standardization, this paper sets out to compare requirements and approaches of these two domains with respect to safety and security aspects. Since from an autonomy perspective, the automotive domain has started earlier and therefore has achieved a higher degree of technical progress, we will start with an overview of the developments in this domain. After that, the paper discusses the requirements on automation and assistance systems in the maritime domain and gives an overview of the developments into this direction within the maritime domain. This then allows us to compare developments in both domains and to derive recommendations for further developments in the maritime domain at the end of this paper.

  1. Navigation in musculoskeletal oncology: An overview

    Directory of Open Access Journals (Sweden)

    Guy Vernon Morris

    2018-01-01

    Full Text Available Navigation in surgery has increasingly become more commonplace. The use of this technological advancement has enabled ever more complex and detailed surgery to be performed to the benefit of surgeons and patients alike. This is particularly so when applying the use of navigation within the field of orthopedic oncology. The developments in computer processing power coupled with the improvements in scanning technologies have permitted the incorporation of navigational procedures into day-to-day practice. A comprehensive search of PubMed using the search terms “navigation”, “orthopaedic” and “oncology” yielded 97 results. After filtering for English language papers, excluding spinal surgery and review articles, this resulted in 38 clinical studies and case reports. These were analyzed in detail by the authors (GM and JS and the most relevant papers reviewed. We have sought to provide an overview of the main types of navigation systems currently available within orthopedic oncology and to assess some of the evidence behind its use.

  2. Propagation Limitations of Navigation and Positioning Systems

    Science.gov (United States)

    1977-02-01

    34Radio Web Navigation System", Technical Description. Stavid Case No. Q-6-359. WOLFF, I., LUCK. D.G.C., 1948, "Principles of Frequency-Modulated Radar...ä IM P/R Bne Cour Psens mer profonde Deep tea research vessels (Hvd^oqraphy- oceanor^hgi qwph/SKsl Navres de recherche sur le plateau conttnentd

  3. 76 FR 63934 - Navigation Safety Advisory Council

    Science.gov (United States)

    2011-10-14

    ..., and aids to navigation systems. The meeting will be open to the public. DATES: NAVSAC will meet... ``Keyword'' box insert ``USCG-2011-0204'' and click ``Search.'' Click the ``Open Docket Folder'' in the...) NAVSAC Task 11-01 Kite Propulsion Systems (Sky Sails). The use of Sky Sails to augment propulsion on...

  4. Houston-Galveston Navigation Channel Shoaling Study

    Science.gov (United States)

    2014-12-01

    Inflows BUFFALO OYSTER CEDAR DICKINSON CLEAR_CRK CHOCOLATE LIVE_OAK ERDC/CHL TR-14-14 70 Wind Wind data used in the 1990 and 2000 efforts were...m) 5 Speed(avg, m/s) 5.71 Vessel Ocean Crescent; Carol Brent; Eagle Dewall; Martin Navigator; Industrial Century Type General cargo; NA; NA

  5. Automated Driftmeter Fused with Inertial Navigation

    Science.gov (United States)

    2014-03-27

    dynamics range. Fortunately, both of these concerns are easily satisfied with today’s ring laser gyro (RLG) or fiber optic gyroscope (FOG) technology...22 FOG fiber optic gyroscope . . . . . . . . . . . . . . . . . . . . . . . . . . 22 KF Kalman filter...The motivation of this research is to address the use of bearing-only measurements taken by an optical sensor to aid an Inertial Navigation System

  6. The Navigation System of the Brain

    Indian Academy of Sciences (India)

    IAS Admin

    position and navigation (Figure 1). Edward Tolman's Idea of Cognitive Maps. Some of the early experiments on spatial learning of animals were performed by psychologist Edward C Tolman during the late. 1940's. Skinner's behaviourist paradigm dominated psychology during that period and most psychologists focussed ...

  7. Gamifying Navigation in Location-Based Applications

    DEFF Research Database (Denmark)

    Nadarajah, Stephanie Githa; Overgaard, Benjamin Nicholas; Pedersen, Peder Walz

    2017-01-01

    Location-based games entertain players usually by interactions at points of interest (POIs). Navigation between POIs often involve the use of either a physical or digital map, not taking advantage of the opportunity available to engage users in activities between POIs. The paper presents riddle s...

  8. Navigable windows of the Northwest Passage

    Science.gov (United States)

    Liu, Xing-he; Ma, Long; Wang, Jia-yue; Wang, Ye; Wang, Li-na

    2017-09-01

    Artic sea ice loss trends support a greater potential for Arctic shipping. The information of sea ice conditions is important for utilizing Arctic passages. Based on the shipping routes given by ;Arctic Marine Shipping Assessment 2009 Report;, the navigable windows of these routes and the constituent legs were calculated by using sea ice concentration product data from 2006 to 2015, by which a comprehensive knowledge of the sea ice condition of the Northwest Passage was achieved. The results showed that Route 4 (Lancaster Sound - Barrow Strait - Prince Regent Inlet and Bellot Strait - Franklin Strait - Larsen Sound - Victoria Strait - Queen Maud Gulf - Dease Strait - Coronation Gulf - Dolphin and Union Strait - Amundsen Gulf) had the best navigable expectation, Route 2 (Parry Channel - M'Clure Strait) had the worst, and the critical legs affecting the navigation of Northwest Passage were Viscount Melville Sound, Franklin Strait, Victoria Strait, Bellot Strait, M'Clure Strait and Prince of Wales Strait. The shortest navigable period of the routes of Northwest Passage was up to 69 days. The methods used and the results of the study can help the selection and evaluation of Arctic commercial routes.

  9. Orchard navigation using derivative free Kalman filtering

    DEFF Research Database (Denmark)

    Hansen, Søren; Bayramoglu, Enis; Andersen, Jens Christian

    2011-01-01

    This paper describes the use of derivative free filters for mobile robot localization and navigation in an orchard. The localization algorithm fuses odometry and gyro measurements with line features representing the surrounding fruit trees of the orchard. The line features are created on basis of 2...

  10. Spatial navigation by congenitally blind individuals.

    Science.gov (United States)

    Schinazi, Victor R; Thrash, Tyler; Chebat, Daniel-Robert

    2016-01-01

    Spatial navigation in the absence of vision has been investigated from a variety of perspectives and disciplines. These different approaches have progressed our understanding of spatial knowledge acquisition by blind individuals, including their abilities, strategies, and corresponding mental representations. In this review, we propose a framework for investigating differences in spatial knowledge acquisition by blind and sighted people consisting of three longitudinal models (i.e., convergent, cumulative, and persistent). Recent advances in neuroscience and technological devices have provided novel insights into the different neural mechanisms underlying spatial navigation by blind and sighted people and the potential for functional reorganization. Despite these advances, there is still a lack of consensus regarding the extent to which locomotion and wayfinding depend on amodal spatial representations. This challenge largely stems from methodological limitations such as heterogeneity in the blind population and terminological ambiguity related to the concept of cognitive maps. Coupled with an over-reliance on potential technological solutions, the field has diffused into theoretical and applied branches that do not always communicate. Here, we review research on navigation by congenitally blind individuals with an emphasis on behavioral and neuroscientific evidence, as well as the potential of technological assistance. Throughout the article, we emphasize the need to disentangle strategy choice and performance when discussing the navigation abilities of the blind population. For further resources related to this article, please visit the WIREs website. © 2015 The Authors. WIREs Cognitive Science published by Wiley Periodicals, Inc.

  11. Robust Pedestrian Navigation for Challenging Applications

    OpenAIRE

    Gilliéron, PY; Renaudin, V

    2009-01-01

    Presentation of a concept for robust indoor navigation. The concept is based on three key elements: - the use of an absolute geographical reference - the hybridisation of complementary technologies - specific motion models. This concept is illustrated by the means of two applications: the urban displacement of blind people and the indoor guidance of fire-fighters

  12. Mobile Screens: The Visual Regime of Navigation

    NARCIS (Netherlands)

    Verhoeff, N.

    2012-01-01

    In this book on screen media, space, and mobility I compare synchronically, as well as diachronically, diverse and variegated screen media - their technologies and practices – as sites for virtual mobility and navigation. Mobility as a central trope can be found on the multiple levels that are

  13. Navigating the Bio-Politics of Childhood

    Science.gov (United States)

    Lee, Nick; Motzkau, Johanna

    2011-01-01

    Childhood research has long shared a bio-political terrain with state agencies in which children figure primarily as "human futures". In the 20th century bio-social dualism helped to make that terrain navigable by researchers, but, as life processes increasingly become key sites of bio-political action, bio-social dualism is becoming…

  14. Celestial Navigation on the Surface of Mars

    Science.gov (United States)

    Malay, Benjamin P.

    2001-05-01

    A simple, accurate, and autonomous method of finding position on the surface of Mars currently does not exist. The goal of this project is to develop a celestial navigation process that will fix a position on Mars with 100-meter accuracy. This method requires knowing the position of the stars and planets referenced to the Martian surface with one arcsecond accuracy. This information is contained in an ephemeris known as the Aeronautical Almanac (from Ares, the god of war) . Naval Observatory Vector Astrometry Subroutines (NOVAS) form the basis of the code used to generate the almanac. Planetary position data come the JPL DE405 Planetary Ephemeris. The theoretical accuracy of the almanac is determined mathematically and compared with the Ephemeris for Physical Observations of Mars contained in the Astronautical Almanac. A preliminary design of an autonomous celestial navigation system is presented. Recommendations of how to integrate celestial navigation into NASA=s current Mars exploration program are also discussed. This project is a useful and much-needed first step towards establishing celestial navigation as a practical way to find position on the surface of Mars.

  15. Redundant Strapdown Laser Gyro Navigation System

    Science.gov (United States)

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

    1976-01-01

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

  16. Vibrobelt: Tactile Navigation Support for Cyclists

    NARCIS (Netherlands)

    Steltenpohl, H.; Bouwer, A.

    2013-01-01

    Tactile displays can be used without demanding the attention from the human visual system, which makes them attractive for use in wayfinding contexts, where visual attention should be directed at traffic and other information in the environment. To investigate the potential of tactile navigation for

  17. The Navigation System of the Brain

    Indian Academy of Sciences (India)

    IAS Admin

    The Navigation System of the Brain. 2014 Nobel Prize in Physiology or Medicine. Prasanna Venkhatesh V. Keywords. Hippocampus, cognitive map, place cells, grid cells. “It is fair to say that, in general, no problems have been exhausted; instead, men have been exhausted by the prob- lems. Soil that appears impoverished ...

  18. NAMMA DC-8 NAVIGATION AND HOUSEKEEPING (ICATS) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The NAMMA DC-8 Navigation and Housekeeping (ICATS) dataset is designed to: 1) interface and process avionics and environmental paramaters from the Navigational...

  19. GRIP DC-8 NAVIGATION AND HOUSEKEEPING DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GRIP DC-8 Navigation and Housekeeping Data contains aircraft navigational data obtained during the GRIP campaign (15 Aug 2010 - 30 Sep 2010). The major goal was...

  20. GRIP DC-8 NAVIGATION AND HOUSEKEEPING DATA V1

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset contains aircraft navigational data obtained during the GRIP campaign (15 Aug 2010 - 30 Sep 2010). The NASA DC-8 is outfitted with a navigational...

  1. Issues in symbol design for electronic displays of navigation information

    Science.gov (United States)

    2004-10-24

    An increasing number of electronic displays, ranging from small hand-held displays for general aviation to installed displays for air transport, are showing navigation information, such as symbols representing navigational aids. The wide range of dis...

  2. Adaptive Landmark-Based Navigation System Using Learning Techniques

    DEFF Research Database (Denmark)

    Zeidan, Bassel; Dasgupta, Sakyasingha; Wörgötter, Florentin

    2014-01-01

    The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal. In...... hexapod robots. As a result, it allows the robots to successfully learn to navigate to distal goals in complex environments.......The goal-directed navigational ability of animals is an essential prerequisite for them to survive. They can learn to navigate to a distal goal in a complex environment. During this long-distance navigation, they exploit environmental features, like landmarks, to guide them towards their goal....... Inspired by this, we develop an adaptive landmark-based navigation system based on sequential reinforcement learning. In addition, correlation-based learning is also integrated into the system to improve learning performance. The proposed system has been applied to simulated simple wheeled and more complex...

  3. GPM Ground Validation Navigation Data ER-2 OLYMPEX V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The GPM Ground Validation NASA ER-2 Navigation Data OLYMPEX dataset supplies navigation data collected by the NASA ER-2 aircraft for flights that occurred during...

  4. Advanced navigation algorithms for precision landing

    Science.gov (United States)

    Zanetti, Renato

    2007-12-01

    A detailed analysis of autonomous navigation algorithms to achieve autonomous precision landing is presented. The problem of integrated attitude determination and inertial navigation is solved. The theoretical results are applied and tested in three different applications. Optimality conditions for constrained quaternion estimation using the Kalman filter are derived. It is common in spacecraft applications to separate the attitude determination from the inertial navigation system. While this approach has worked in the past, it inevitably degrades the navigation performance when the correlations between the two systems are not correctly accounted for. It is shown how to optimally include an attitude determination algorithm into the Kalman filter. When the conditions to achieve optimality are not met, it is shown how to achieve sub-optimality by properly accounting for the correlation. The traditional approach to inertial navigation is to employ the inertial measurement unit (IMU) outputs to propagate the estimated states forward in time, rather then use them to update the state. This approach, known as dead-reckoning, allows for a simplified dynamics model, which in turn reduces the process noise, a contributor to the estimation error. A detailed covariance analysis of dead-reckoning Mars entry navigation is performed. The contribution of various sources of IMU errors are explicitly accounted for and the filter performance is validated through Monte Carlo analysis. The drawback of dead-reckoning is that this approach prevents the inertial measurements from reducing the uncertainty of the estimated states. While this shortcoming can be compensated by the availability of other measurements, it becomes crucial when the IMU is the only sensor to provide measurements. Such a situation arises, for example, during Mars atmospheric entry. In the second application of this work, IMU measurements from a NASA mission are processed in an extended Kalman filter, and the results

  5. Fast Acceleration of ``Killer'' Electrons and Energetic Ions by Interplanetary Shock Stimulated ULF Waves in the Inner Magnetosphere

    Science.gov (United States)

    Zong, Q.

    2010-12-01

    Energetic electrons and ions in the Van Allen radiation belt are the number one space weather threat. How the energetic particles are accelerated in the Van Allen radiation belts is one of major problems in the space physics. Very Low Frequency (VLF) wave-particle interaction has been considered as one of primary electron acceleration mechanisms because electron cyclotron resonances can easily occur in the VLF frequency range. However, recently, by using four Cluster spacecraft observations, we have found that after interplanetary shocks impact on the Earth’s magnetosphere, the acceleration of the energetic electrons in the radiation belt started nearly immediately and lasted for a few hours. The time scale (a few days) for traditional acceleration mechanism of VLF wave-particle interaction, as proposed by Horne et al. [1], to accelerate electrons to relativistic energies is too long to explain the observations. It is further found that interplanetary shocks or solar wind pressure pulses with even small dynamic pressure change can play a non-negligible role in the radiation belt dynamics. Interplanetary shocks interact with and the Earth’s magnetosphere manifests many fundamental important space physics phenomena including energetic particle acceleration. The mechanism of fast acceleration of energetic electrons in the radiation belt response to interplanetary shock impact contains three contributing parts: (1) the initial adiabatic acceleration due to the strong shock-related magnetic field compression; (2) then followed by the drift-resonant acceleration with poloidal ULF waves excited at different L-shells; and (3) particle acceleration due to fast damping electric fields associated with ULF waves. Particles will have a net acceleration since particles in the second half circle will not lose all of the energy gained in the first half cycle. The results reported in this paper cast new lights on understanding the acceleration of energetic particles in the

  6. Precision Global Navigation Satellite System Relative Navigation & Timekeeping for Miniaturized Distributed Space Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to provide unprecedented precision real-time absolute and relative navigation capabilities to formations of nanosatellites using signals...

  7. Lunar Navigator - A Miniature, Fully Autonomous, Lunar Navigation, Surveyor, and Range Finder System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm proposes to design and develop a fully autonomous Lunar Navigator based on our MicroMak miniature star sensor and a gravity gradiometer similar to one on a...

  8. Lunar Navigator - A Miniature, Fully Autonomous, Lunar Navigation, Surveyor, and Range Finder System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm will use existing hardware and software from related programs to create a prototype Lunar Navigation Sensor (LNS) early in Phase II, such that most of the...

  9. Lunar Navigator - A Miniature, Fully Autonomous, Lunar Navigation, Surveyor, and Range Finder System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcosm will use existing hardware and software from related programs to create a prototype Lunar Navigation Sensor (LNS) early in Phase II, such that most of the...

  10. Navigated Waterways of Louisiana, Geographic NAD83, LOSCO (1999) [navigated_waterways_LOSCO_1999

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a line dataset of navigated waterways fitting the LOSCO definition: it has been traveled by vessels transporting 10,000 gallons of oil or fuel as determined...

  11. Evaluation of navigation interfaces in virtual environments

    Science.gov (United States)

    Mestre, Daniel R.

    2014-02-01

    When users are immersed in cave-like virtual reality systems, navigational interfaces have to be used when the size of the virtual environment becomes larger than the physical extent of the cave floor. However, using navigation interfaces, physically static users experience self-motion (visually-induced vection). As a consequence, sensorial incoherence between vision (indicating self-motion) and other proprioceptive inputs (indicating immobility) can make them feel dizzy and disoriented. We tested, in two experimental studies, different locomotion interfaces. The objective was twofold: testing spatial learning and cybersickness. In a first experiment, using first-person navigation with a flystick ®, we tested the effect of sensorial aids, a spatialized sound or guiding arrows on the ground, attracting the user toward the goal of the navigation task. Results revealed that sensorial aids tended to impact negatively spatial learning. Moreover, subjects reported significant levels of cybersickness. In a second experiment, we tested whether such negative effects could be due to poorly controlled rotational motion during simulated self-motion. Subjects used a gamepad, in which rotational and translational displacements were independently controlled by two joysticks. Furthermore, we tested first- versus third-person navigation. No significant difference was observed between these two conditions. Overall, cybersickness tended to be lower, as compared to experiment 1, but the difference was not significant. Future research should evaluate further the hypothesis of the role of passively perceived optical flow in cybersickness, but manipulating the virtual environment'sperrot structure. It also seems that video-gaming experience might be involved in the user's sensitivity to cybersickness.

  12. Integrated and Multi-Function Navigation (Les Systemes de Navigation Integres Multifunctions)

    Science.gov (United States)

    1992-11-01

    soit. indirectement . de la linftritt escomptde . Les &~placements de la masse stsmique sont mesurds au point milieu du pont capacitif defina par le d...Presque unique ost cdcldi au traitement du signal. au contr6le entlerement digital. des boucles et au traitemont do Ia navigation GPS Los transferts do...navigation hybrtde. grrice a ’utilisation d’un algorthme de Kalman-Bierman numeriquement stable et a une. entin. montrer les benefices cle la

  13. 14 CFR 27.1303 - Flight and navigation instruments.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight and navigation instruments. 27.1303 Section 27.1303 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... navigation instruments. The following are the required flight and navigation instruments: (a) An airspeed...

  14. 14 CFR 23.1303 - Flight and navigation instruments.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flight and navigation instruments. 23.1303... General § 23.1303 Flight and navigation instruments. The following are the minimum required flight and navigation instruments: (a) An airspeed indicator. (b) An altimeter. (c) A direction indicator (nonstabilized...

  15. 76 FR 27337 - Houston/Galveston Navigation Safety Advisory Committee

    Science.gov (United States)

    2011-05-11

    ... DEPARTMENT OF HOMELAND SECURITY Coast Guard [USCG-2010-1116] Houston/Galveston Navigation Safety...: The Houston/Galveston Navigation Safety Advisory Committee postponed its originally scheduled February... Houston Ship Channel, and various other navigation safety matters in the Galveston Bay area. The meeting...

  16. 46 CFR 25.10-3 - Navigation light certification requirements.

    Science.gov (United States)

    2010-10-01

    ... on which the light was type-tested. (viii) Identification of bulb used in the compliance test. (b) If... 46 Shipping 1 2010-10-01 2010-10-01 false Navigation light certification requirements. 25.10-3... Navigation Lights § 25.10-3 Navigation light certification requirements. (a) Except as provided by paragraph...

  17. 22 CFR 401.25 - Government brief regarding navigable waters.

    Science.gov (United States)

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Government brief regarding navigable waters. 401... PROCEDURE Applications § 401.25 Government brief regarding navigable waters. When in the opinion of the Commission it is desirable that a decision should be rendered which affects navigable waters in a manner or...

  18. NAVIGATION AND LANDING AVIONICS INTEGRATED SYSTEM PROGRESS TREND

    Directory of Open Access Journals (Sweden)

    2016-01-01

    Full Text Available Advantages and disadvantages of various navigation methods are considered. The main advantage of an inertial method of navigation consisting in a high noise stability is given. The drawback of this navigation method consisting in accumulating mistakes by the time is given. The benefit of satellite navigation systems from the point of view of their glob- ality and high precision of measurement is proved. Disadvantages and advantages of a rho-rho navigation in comparison with satellite navigation systems are considered. The main activities of a complex using of satellite and radar navigation aids, and also satellite and inertial navigation aids are given. Various systems of complex use of a rho-rho navigation and satellite navigation systems are considered. The common important faults inherent in methods and systems according to patents are in detail considered. Methods of a complex using of inertial and satellite navigation systems in the form of iner- tial system use are given in a complex with the satellite receiver in contours of phase and frequency autocontrol of a satel- lite signal to increase accuracy and continuity of a signal from the receiver, and also in the form of a satellite method use with the differential mode to increase accuracy of an inertial method with correcting the inertial system signal are given. The analysis of various patents for complex methods of navigation is carried out.

  19. Biologically Inspired Waveform Diversity for Synthetic Autonomous Navigation Sensing

    Science.gov (United States)

    2009-11-01

    navigation, collision avoidance, ambiguity SUMMARY Echolocating mammals such as bats , whales and dolphins have been using waveform diversity for...we have adopted. Mammals such as bats use echolocation to perform autonomous navigation (or more strictly orientation), detection and classification...understand how bats exploit echolocation for autonomous navigation and collision avoidance we can then begin to build this into synthetic systems

  20. PRIVATE GRAPHS – ACCESS RIGHTS ON GRAPHS FOR SEAMLESS NAVIGATION

    Directory of Open Access Journals (Sweden)

    W. Dorner

    2016-06-01

    Full Text Available After the success of GNSS (Global Navigational Satellite Systems and navigation services for public streets, indoor seems to be the next big development in navigational services, relying on RTLS – Real Time Locating Services (e.g. WIFI and allowing seamless navigation. In contrast to navigation and routing services on public streets, seamless navigation will cause an additional challenge: how to make routing data accessible to defined users or restrict access rights for defined areas or only to parts of the graph to a defined user group? The paper will present case studies and data from literature, where seamless and especially indoor navigation solutions are presented (hospitals, industrial complexes, building sites, but the problem of restricted access rights was only touched from a real world, but not a technical perspective. The analysis of case studies will show, that the objective of navigation and the different target groups for navigation solutions will demand well defined access rights and require solutions, how to make only parts of a graph to a user or application available to solve a navigational task. The paper will therefore introduce the concept of private graphs, which is defined as a graph for navigational purposes covering the street, road or floor network of an area behind a public street and suggest different approaches how to make graph data for navigational purposes available considering access rights and data protection, privacy and security issues as well.

  1. Time and Motion Study of a Community Patient Navigator

    Directory of Open Access Journals (Sweden)

    Sara S. Phillips

    2014-04-01

    Full Text Available Research on patient navigation has focused on validating the utility of navigators by defining their roles and analyzing their effects on patient outcomes, patient satisfaction, and cost effectiveness. Patient navigators are increasingly used outside the research context, and their roles without research responsibilities may look very different. This pilot study captured the activities of a community patient navigator for uninsured women with a positive screening test for breast cancer, using a time and motion approach over a period of three days. We followed the actions of this navigator minute by minute to assess the relative ratios of actions performed and to identify areas for time efficiency improvement to increase direct time with patients. This novel approach depicts the duties of a community patient navigator no longer fettered by navigation logs, research team meetings, surveys, and the consent process. We found that the community patient navigator was able to spend more time with patients in the clinical context relative to performing paperwork or logging communication with patients as a result of her lack of research responsibilities. By illuminating how community patient navigation functions as separate from the research setting, our results will inform future hiring and training of community patient navigators, system design and operations for improving the efficiency and efficacy of navigators, and our understanding of what community patient navigators do in the absence of research responsibilities.

  2. Fault-tolerant Sensor Fusion for Marine Navigation

    DEFF Research Database (Denmark)

    Blanke, Mogens

    2006-01-01

    Reliability of navigation data are critical for steering and manoeuvring control, and in particular so at high speed or in critical phases of a mission. Should faults occur, faulty instruments need be autonomously isolated and faulty information discarded. This paper designs a navigation solution...... events where the fault-tolerant sensor fusion provided uninterrupted navigation data despite temporal instrument defects...

  3. Benefits of multisensory presentation on perception, memory and navigation

    NARCIS (Netherlands)

    Philippi, T.G.|info:eu-repo/dai/nl/313711577

    2012-01-01

    Navigation is the process of planning and following routes to travel from the current location to a target location. In comparison with real world navigation, we have considerable difficulty with navigation in virtual environments. An important cause is that less information is presented in a

  4. 47 CFR 22.365 - Antenna structures; air navigation safety.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Antenna structures; air navigation safety. 22... Antenna structures; air navigation safety. Licensees that own their antenna structures must not allow these antenna structures to become a hazard to air navigation. In general, antenna structure owners are...

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

    Science.gov (United States)

    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.

  6. SLS Navigation Model-Based Design Approach

    Science.gov (United States)

    Oliver, T. Emerson; Anzalone, Evan; Geohagan, Kevin; Bernard, Bill; Park, Thomas

    2018-01-01

    The SLS Program chose to implement a Model-based Design and Model-based Requirements approach for managing component design information and system requirements. This approach differs from previous large-scale design efforts at Marshall Space Flight Center where design documentation alone conveyed information required for vehicle design and analysis and where extensive requirements sets were used to scope and constrain the design. The SLS Navigation Team has been responsible for the Program-controlled Design Math Models (DMMs) which describe and represent the performance of the Inertial Navigation System (INS) and the Rate Gyro Assemblies (RGAs) used by Guidance, Navigation, and Controls (GN&C). The SLS Navigation Team is also responsible for the navigation algorithms. The navigation algorithms are delivered for implementation on the flight hardware as a DMM. For the SLS Block 1-B design, the additional GPS Receiver hardware is managed as a DMM at the vehicle design level. This paper provides a discussion of the processes and methods used to engineer, design, and coordinate engineering trades and performance assessments using SLS practices as applied to the GN&C system, with a particular focus on the Navigation components. These include composing system requirements, requirements verification, model development, model verification and validation, and modeling and analysis approaches. The Model-based Design and Requirements approach does not reduce the effort associated with the design process versus previous processes used at Marshall Space Flight Center. Instead, the approach takes advantage of overlap between the requirements development and management process, and the design and analysis process by efficiently combining the control (i.e. the requirement) and the design mechanisms. The design mechanism is the representation of the component behavior and performance in design and analysis tools. The focus in the early design process shifts from the development and

  7. 33 CFR 207.600 - Rochester (Charlotte) Harbor, N.Y.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Rochester (Charlotte) Harbor, N.Y.; use, administration, and navigation. 207.600 Section 207.600 Navigation and Navigable Waters CORPS OF... (Charlotte) Harbor, N.Y.; use, administration, and navigation. (a)-(b) (c) No vessel shall moor or anchor to...

  8. 33 CFR 207.580 - Buffalo Harbor, N.Y.; use, administration, and navigation.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Buffalo Harbor, N.Y.; use, administration, and navigation. 207.580 Section 207.580 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.580 Buffalo Harbor, N.Y.; use...

  9. 33 CFR 209.170 - Violations of laws protecting navigable waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Violations of laws protecting navigable waters. 209.170 Section 209.170 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF... navigable waters. (a) [Reserved] (b) Injuries to Government works. Section 14 of the River and Harbor Act of...

  10. 33 CFR 64.16 - Duration of marking on sunken vessels in navigable waters.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Duration of marking on sunken vessels in navigable waters. 64.16 Section 64.16 Navigation and Navigable Waters COAST GUARD, DEPARTMENT... Sunken Vessels and Other Obstructions § 64.16 Duration of marking on sunken vessels in navigable waters...

  11. 33 CFR 149.505 - What are the general requirements for aids to navigation?

    Science.gov (United States)

    2010-07-01

    ... for aids to navigation? 149.505 Section 149.505 Navigation and Navigable Waters COAST GUARD... EQUIPMENT Aids to Navigation General § 149.505 What are the general requirements for aids to navigation? The following requirements apply to navigation aids under this subpart: (a) Section 66.01-5 of this chapter, on...

  12. Indoor inertial navigation application for smartphones with Android

    Science.gov (United States)

    Kamiński, Ł.; Tarapata, G.

    2015-09-01

    Inertial navigation is widely used by the military, in logistics and sailing. In mobile devices, inertial sensors are mostly used as a support for GPS and Wi-Fi-based navigation systems. Inertial-based navigation might prove useful on mobile devices running Android OS. At present, in spite of the accelerometer sensor's precision having been greatly improved, as well as the devices' computing power continuously rising, inertial navigation's precision still suffers. For smartphones, the key solution seems to be the usage of sensor fusion and signal smart filtering, both discussed in this paper. The paper also describes implementation of inertial navigation in Android devices, their analysis as well as test results.

  13. On the relationship between interplanetary coronal mass ejections and magnetic clouds

    Directory of Open Access Journals (Sweden)

    E. K. J. Kilpua

    2013-07-01

    Full Text Available The relationship of magnetic clouds (MCs to interplanetary coronal mass ejections (ICMEs is still an open issue in space research. The view that all ICMEs would originate as magnetic flux ropes has received increasing attention, although near the orbit of the Earth only about one-third of ICMEs show clear MC signatures and often the MC occupies only a portion of the more extended region showing ICME signatures. In this work we analyze 79 events between 1996 and 2009 reported in existing ICME/MC catalogs (Wind magnetic cloud list and the Richardson and Cane ICME list using near-Earth observations by ACE (Advanced Composition Explorer and Wind. We perform a systematic comparison of cases where ICME and MC signatures coincided and where ICME signatures extended significantly beyond the MC boundaries. We find clear differences in the characteristics of these two event types. In particular, the events where ICME signatures continued more than 6 h past the MC rear boundary had 2.7 times larger speed difference between the ICME's leading edge and the preceding solar wind, 1.4 times higher magnetic fields, 2.1 times larger widths and they experienced three times more often strong expansion than the events for which the rear boundaries coincided. The events with significant mismatch in MC and ICME boundary times were also embedded in a faster solar wind and the majority of them were observed close to the solar maximum. Our analysis shows that the sheath, the MC and the regions of ICME-related plasma in front and behind the MC have different magnetic field, plasma and charge state characteristics, thus suggesting that these regions separate already close to the Sun. Our study shows that the geometrical effect (the encounter through the CME leg and/or far from the flux rope center does not contribute much to the observed mismatch in the MC and ICME boundary times.

  14. Development of the isotopic analysis of individual macroparticles: a study of desert dust and interplanetary dust

    International Nuclear Information System (INIS)

    Aleon, Jerome

    2001-01-01

    During this thesis a new analytical technique has been developed to allow the determination of isotopic ratios in microparticles. This technique is based on the imaging properties of the IMS 1270 ion microprobe in CRPG in Nancy. The development of quantitative isotopic imaging allows the determination of the 18 O/ 16 O ratio of individual macroparticles having a size < 2 μm with a 3 to 4 % precision and to map, with ∼ 1 μm lateral resolution, the isotopic variation of hydrogen in particles having a size of 10 μm. This new technique was used to study the problem of the origin of Saharan dust particles, indeed the distribution of 18 O/ 16 O ratios in individual quartz grains is shown to be a characteristic fingerprint of the geology of the source area. The determination of oxygen isotopic ratio in individual grains of a given dust storm above the Atlantic Ocean indicates that the likely source area of this storm is the Air-Tenere region. This result has strong implications for the cycle of Saharan dust in the atmosphere and the processes of dust suspension into the atmosphere. Mapping the D/H variations in 4 interplanetary dust particles collected in the stratosphere by the NASA shows that these particles contain several distinct types of organic matter having an interstellar origin. These organic matters can be related to polymers measured in cornets and carbonaceous chondrites. The presence of these different polymers inside one single particle suggests that the most primitive materials of the solar system may be related to each other. (author) [fr

  15. Prompt Acceleration of Magnetospheric Electrons to Ultrarelativistic Energies by the 17 March 2015 Interplanetary Shock

    Science.gov (United States)

    Kanekal, S. G.; Baker, D. N.; Fennell, J. F.; Jones, A.; Schiller, Q.; Richardson, I.G.; Li, X.; Turner, D. L.; Califf, S.; Claudepierre, S. G.; hide

    2016-01-01

    Trapped electrons in Earth's outer Van Allen radiation belt are influenced profoundly by solar phenomena such as high-speed solar wind streams, coronal mass ejections (CME), and interplanetary (IP) shocks. In particular, strong IP shocks compress the magnetosphere suddenly and result in rapid energization of electrons within minutes. It is believed that the electric fields induced by the rapid change in the geomagnetic field are responsible for the energization. During the latter part of March 2015, a CME impact led to the most powerful geomagnetic storm (minimum Dst = -223 nT at 17 March, 23 UT) observed not only during the Van Allen Probe era but also the entire preceding decade. Magnetospheric response in the outer radiation belt eventually resulted in elevated levels of energized electrons. The CME itself was preceded by a strong IP shock whose immediate effects vis-a-vis electron energization were observed by sensors on board the Van Allen Probes. The comprehensive and high-quality data from the Van Allen Probes enable the determination of the location of the electron injection, timescales, and spectral aspects of the energized electrons. The observations clearly show that ultrarelativistic electrons with energies E greater than 6 MeV were injected deep into the magnetosphere at L approximately equals 3 within about 2 min of the shock impact. However, electrons in the energy range of approximately equals 250 keV to approximately equals 900 keV showed no immediate response to the IP shock. Electric and magnetic fields resulting from the shock-driven compression complete the comprehensive set of observations that provide a full description of the near-instantaneous electron energization.

  16. Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network.

    Science.gov (United States)

    Aasi, J; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ajith, P; Alemic, A; Allen, B; Allocca, A; Amariutei, D; Andersen, M; Anderson, R A; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J S; Ast, S; Aston, S M; Astone, P; Aufmuth, P; Augustus, H; Aulbert, C; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barbet, M; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bauchrowitz, J; Bauer, Th S; Baune, C; Bavigadda, V; Behnke, B; Bejger, M; Beker, M G; Belczynski, C; Bell, A S; Bell, C; Bergmann, G; Bersanetti, D; Bertolini, A; Betzwieser, J; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Biwer, C; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bloemen, S; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, Sukanta; Bosi, L; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Buchman, S; Buikema, A; Bulik, T; Bulten, H J; Buonanno, A; Burman, R; Buskulic, D; Buy, C; Cadonati, L; Cagnoli, G; Calderón Bustillo, J; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castaldi, G; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Celerier, C; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Cho, M; Chow, J H; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, D E; Clark, J A; Clayton, J H; Cleva, F; Coccia, E; Cohadon, P-F; Colla, A; Collette, C; Colombini, M; Cominsky, L; Constancio, M; Conte, A; Cook, D; Corbitt, T R; Cornish, N; Corsi, A; Costa, C A; Coughlin, M W; Coulon, J-P; Countryman, S; Couvares, P; Coward, D M; Cowart, M J; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Croce, R P; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Cutler, C; Dahl, K; Dal Canton, T; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; DeBra, D; Debreczeni, G; Degallaix, J; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M; Dickson, J; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Dolique, V; Dominguez, E; Donovan, F; Dooley, K L; Doravari, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Ducrot, M; Dwyer, S; Eberle, T; Edo, T; Edwards, M; Effler, A; Eggenstein, H-B; Ehrens, P; Eichholz, J; Eikenberry, S S; Endrőczi, G; Essick, R; Etzel, T; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fan, X; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fazi, D; Fehrmann, H; Fejer, M M; Feldbaum, D; Feroz, F; Ferrante, I; Ferreira, E C; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Fournier, J-D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gair, J R; Gammaitoni, L; Gaonkar, S; Garufi, F; Gehrels, N; Gemme, G; Gendre, B; Genin, E; Gennai, A; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Gräf, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C J; Gushwa, K; Gustafson, E K; Gustafson, R; Ha, J; Hall, E D; Hamilton, W; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hannam, M D; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hart, M; Hartman, M T; Haster, C-J; Haughian, K; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Hofman, D; Holt, K; Hopkins, P; Horrom, T; Hoske, D; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Huerta, E; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Idrisy, A; Ingram, D R; Inta, R; Islas, G; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; Jang, H; Jaranowski, P; Ji, Y; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; Haris, K; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karlen, J; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, H; Kaufer, S; Kaur, T; Kawabe, K; Kawazoe, F; Kéfélian, F; Keiser, G M; Keitel, D; Kelley, D B; Kells, W; Keppel, D G; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, C; Kim, K; Kim, N G; Kim, N; Kim, S; Kim, Y-M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I; Kozak, D B; Kringel, V; Krishnan, B; Królak, A; Kuehn, G; Kumar, A; Kumar, D Nanda; Kumar, P; Kumar, R; Kuo, L; Kutynia, A; Lam, P K; Landry, M; Lantz, B; Larson, S; Lasky, P D; Lazzarini, A; Lazzaro, C; Leaci, P; Leavey, S; Lebigot, E O; Lee, C H; Lee, H K; Lee, H M; Lee, J; Lee, P J; Leonardi, M; Leong, J R; Leonor, I; Le Roux, A; Leroy, N; Letendre, N; Levin, Y; Levine, B; Lewis, J; Li, T G F; Libbrecht, K; Libson, A; Lin, A C; Littenberg, T B; Lockerbie, N A; Lockett, V; Lodhia, D; Loew, K; Logue, J; Lombardi, A L; Lopez, E; Lorenzini, M; Loriette, V; Lormand, M; Losurdo, G; Lough, J; Lubinski, M J; Lück, H; Lundgren, A P; Ma, Y; Macdonald, E P; MacDonald, T; Machenschalk, B; MacInnis, M; Macleod, D M; Magaña-Sandoval, F; Magee, R; Mageswaran, M; Maglione, C; Mailand, K; Majorana, E; Maksimovic, I; Malvezzi, V; Man, N; Manca, G M; Mandel, I; Mandic, V; Mangano, V; Mangini, N M; 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Neri, I; Neri, M; Newton, G; Nguyen, T; Nielsen, A B; Nissanke, S; Nitz, A H; Nocera, F; Nolting, D; Normandin, M E N; Nuttall, L K; Ochsner, E; O'Dell, J; Oelker, E; Oh, J J; Oh, S H; Ohme, F; Omar, S; Oppermann, P; Oram, R; O'Reilly, B; Ortega, W; O'Shaughnessy, R; Osthelder, C; Ottaway, D J; Ottens, R S; Overmier, H; Owen, B J; Padilla, C; Pai, A; Palashov, O; Palomba, C; Pan, H; Pan, Y; Pankow, C; Paoletti, F; Papa, M A; Paris, H; Pasqualetti, A; Passaquieti, R; Passuello, D; Pedraza, M; Pele, A; Penn, S; Perreca, A; Phelps, M; Pichot, M; Pickenpack, M; Piergiovanni, F; Pierro, V; Pinard, L; Pinto, I M; Pitkin, M; Poeld, J; Poggiani, R; Poteomkin, A; Powell, J; Prasad, J; Predoi, V; Premachandra, S; Prestegard, T; Price, L R; Prijatelj, M; Privitera, S; Prodi, G A; Prokhorov, L; Puncken, O; Punturo, M; Puppo, P; Pürrer, M; Qin, J; Quetschke, V; Quintero, E; Quitzow-James, R; Raab, F J; Rabeling, D S; Rácz, I; Radkins, H; Raffai, P; Raja, S; Rajalakshmi, G; Rakhmanov, M; Ramet, C; Ramirez, K; 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Souradeep, T; Staley, A; Stebbins, J; Steinke, M; Steinlechner, J; Steinlechner, S; Stephens, B C; Steplewski, S; Stevenson, S; Stone, R; Stops, D; Strain, K A; Straniero, N; Strigin, S; Sturani, R; Stuver, A L; Summerscales, T Z; Susmithan, S; Sutton, P J; Swinkels, B; Tacca, M; Talukder, D; Tanner, D B; Tao, J; Tarabrin, S P; Taylor, R; Tellez, G; Thirugnanasambandam, M P; Thomas, M; Thomas, P; Thorne, K A; Thorne, K S; Thrane, E; Tiwari, V; Tokmakov, K V; Tomlinson, C; Tonelli, M; Torres, C V; Torrie, C I; Travasso, F; Traylor, G; Tse, M; Tshilumba, D; Tuennermann, H; Ugolini, D; Unnikrishnan, C S; Urban, A L; Usman, S A; Vahlbruch, H; Vajente, G; Valdes, G; Vallisneri, M; van Beuzekom, M; van den Brand, J F J; Van Den Broeck, C; van der Sluys, M V; van Heijningen, J; van Veggel, A A; Vass, S; Vasúth, M; Vaulin, R; Vecchio, A; Vedovato, G; Veitch, J; Veitch, P J; Venkateswara, K; Verkindt, D; Vetrano, F; Viceré, A; Vincent-Finley, R; Vinet, J-Y; Vitale, S; Vo, T; Vocca, H; Vorvick, C; Vousden, W D; Vyachanin, S P; Wade, A R; Wade, L; Wade, M; Walker, M; Wallace, L; Walsh, S; Wang, M; Wang, X; Ward, R L; Was, M; Weaver, B; Wei, L-W; Weinert, M; Weinstein, A J; Weiss, R; Welborn, T; Wen, L; Wessels, P; West, M; Westphal, T; Wette, K; Whelan, J T; White, D J; Whiting, B F; Wiesner, K; Wilkinson, C; Williams, K; Williams, L; Williams, R; Williams, T D; Williamson, A R; Willis, J L; Willke, B; Wimmer, M; Winkler, W; Wipf, C C; Wiseman, A G; Wittel, H; Woan, G; Wolovick, N; Worden, J; Wu, Y; Yablon, J; Yakushin, I; Yam, W; Yamamoto, H; Yancey, C C; Yang, H; Yoshida, S; Yvert, M; Zadrożny, A; Zanolin, M; Zendri, J-P; Zhang, Fan; Zhang, L; Zhao, C; Zhu, H; Zhu, X J; Zucker, M E; Zuraw, S; Zweizig, J; Aptekar, R L; Atteia, J L; Cline, T; Connaughton, V; Frederiks, D D; Golenetskii, S V; Hurley, K; Krimm, H A; Marisaldi, M; Pal'shin, V D; Palmer, D; Svinkin, D S; Terada, Y; von Kienlin, A

    2014-07-04

    We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

  17. Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by the Interplanetary Network

    Science.gov (United States)

    Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Acernese, F.; Blackbum, L.; Camp, J. B.; Gehrels, N.; Graff, P. B.; hide

    2014-01-01

    We present the results of a search for gravitational waves associated with 223 gamma ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(exp-2) solar mass c(exp 2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

  18. AVERAGE SPATIAL DISTRIBUTION OF COSMIC RAYS BEHIND THE INTERPLANETARY SHOCK—GLOBAL MUON DETECTOR NETWORK OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kozai, M.; Munakata, K.; Kato, C. [Department of Physics, Shinshu University, Matsumoto, Nagano 390-8621 (Japan); Kuwabara, T. [Graduate School of Science, Chiba University, Chiba City, Chiba 263-8522 (Japan); Rockenbach, M.; Lago, A. Dal; Braga, C. R.; Mendonça, R. R. S. [National Institute for Space Research (INPE), 12227-010 São José dos Campos, SP (Brazil); Schuch, N. J. [Southern Regional Space Research Center (CRS/INPE), P.O. Box 5021, 97110-970, Santa Maria, RS (Brazil); Jassar, H. K. Al; Sharma, M. M. [Physics Department, Kuwait University, P.O. Box 5969 Safat, 13060 (Kuwait); Duldig, M. L.; Humble, J. E. [School of Physical Sciences, University of Tasmania, Hobart, Tasmania 7001 (Australia); Evenson, P. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Sabbah, I. [Department of Natural Sciences, College of Health Sciences, Public Authority of Applied Education and Training, Kuwait City 72853 (Kuwait); Tokumaru, M., E-mail: 13st303f@shinshu-u.ac.jp, E-mail: kmuna00@shinshu-u.ac.jp [Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Aichi 464-8601 (Japan)

    2016-07-10

    We analyze the galactic cosmic ray (GCR) density and its spatial gradient in Forbush Decreases (FDs) observed with the Global Muon Detector Network (GMDN) and neutron monitors (NMs). By superposing the GCR density and density gradient observed in FDs following 45 interplanetary shocks (IP-shocks), each associated with an identified eruption on the Sun, we infer the average spatial distribution of GCRs behind IP-shocks. We find two distinct modulations of GCR density in FDs, one in the magnetic sheath and the other in the coronal mass ejection (CME) behind the sheath. The density modulation in the sheath is dominant in the western flank of the shock, while the modulation in the CME ejecta stands out in the eastern flank. This east–west asymmetry is more prominent in GMDN data responding to ∼60 GV GCRs than in NM data responding to ∼10 GV GCRs, because of the softer rigidity spectrum of the modulation in the CME ejecta than in the sheath. The geocentric solar ecliptic- y component of the density gradient, G {sub y}, shows a negative (positive) enhancement in FDs caused by the eastern (western) eruptions, while G {sub z} shows a negative (positive) enhancement in FDs caused by the northern (southern) eruptions. This implies that the GCR density minimum is located behind the central flank of IP-shocks and propagating radially outward from the location of the solar eruption. We also confirmed that the average G {sub z} changes its sign above and below the heliospheric current sheet, in accord with the prediction of the drift model for the large-scale GCR transport in the heliosphere.

  19. AVERAGE SPATIAL DISTRIBUTION OF COSMIC RAYS BEHIND THE INTERPLANETARY SHOCK—GLOBAL MUON DETECTOR NETWORK OBSERVATIONS

    International Nuclear Information System (INIS)

    Kozai, M.; Munakata, K.; Kato, C.; Kuwabara, T.; Rockenbach, M.; Lago, A. Dal; Braga, C. R.; Mendonça, R. R. S.; Schuch, N. J.; Jassar, H. K. Al; Sharma, M. M.; Duldig, M. L.; Humble, J. E.; Evenson, P.; Sabbah, I.; Tokumaru, M.

    2016-01-01

    We analyze the galactic cosmic ray (GCR) density and its spatial gradient in Forbush Decreases (FDs) observed with the Global Muon Detector Network (GMDN) and neutron monitors (NMs). By superposing the GCR density and density gradient observed in FDs following 45 interplanetary shocks (IP-shocks), each associated with an identified eruption on the Sun, we infer the average spatial distribution of GCRs behind IP-shocks. We find two distinct modulations of GCR density in FDs, one in the magnetic sheath and the other in the coronal mass ejection (CME) behind the sheath. The density modulation in the sheath is dominant in the western flank of the shock, while the modulation in the CME ejecta stands out in the eastern flank. This east–west asymmetry is more prominent in GMDN data responding to ∼60 GV GCRs than in NM data responding to ∼10 GV GCRs, because of the softer rigidity spectrum of the modulation in the CME ejecta than in the sheath. The geocentric solar ecliptic- y component of the density gradient, G y , shows a negative (positive) enhancement in FDs caused by the eastern (western) eruptions, while G z shows a negative (positive) enhancement in FDs caused by the northern (southern) eruptions. This implies that the GCR density minimum is located behind the central flank of IP-shocks and propagating radially outward from the location of the solar eruption. We also confirmed that the average G z changes its sign above and below the heliospheric current sheet, in accord with the prediction of the drift model for the large-scale GCR transport in the heliosphere.

  20. A Study of the Interplanetary Signatures of Earth-Arriving CMEs

    Science.gov (United States)

    Akiyama, S.; Yashiro, S.; Gopalswamy, N.; Xie, H.; Makela, P. A.; Kay, C.

    2017-12-01

    We studied interplanetary (IP) signatures associated with coronal mass ejections (CMEs) that are likely to reach Earth. In order to find Earth- arriving CMEs, we started with disk-center CMEs originating within 30 degrees from the central meridian and the equator. Using the side-view images from the STEREO mission, we excluded CMEs that faded out before reaching the Earth orbit, or were captured by other CMEs, or erupted away from the ecliptic plane. We found 61 Earth- arriving CMEs during 2009/10/01 - 2012/07/31 (inclusive). Though all events were observed to reach Earth in the STEREO/HI2 field of view, only 34 out of 61 events (56%) were associated with magnetic cloud (MC) or ejecta (EJ) observed by ACE or Wind. We compared the CME characteristics associated with 9 MCs, 25 EJs, and 27 no- clear- signature (NCS) events to find out what might cause the difference in the IP signatures. To avoid projection effects, we used coronagraph images obtained by the STEREO mission. The average speed (width) of CMEs associated with MCs, EJs, and NCSs are 484 km/s (104°), 663 km/s (135°), and 595 km/s (144°), respectively. CMEs associated with MCs tend to be less energetic than other types in our dataset. We also checked the coronal holes (CHs) near the CME source to examine the effect of the CME deflection. In the case of MCs and EJs, only 22% (2/9) and 28% (7/25) events have CHs near the source, while 48% (13/27) NCS events have nearby CHs. We discuss what factors near the Sun cause the observed differences at Earth.