The Experts below are selected from a list of 2238 Experts worldwide ranked by ideXlab platform

Susan Macmillan - One of the best experts on this subject based on the ideXlab platform.

  • operations of the world data centre for Geomagnetism edinburgh
    Data Science Journal, 2013
    Co-Authors: Sarah Reay, Ellen Clarke, Ewan Dawson, Susan Macmillan
    Abstract:

    The British Geological Survey has operated a World Data Centre for Geomagnetism since 1966. Geomagnetic time-series data from around 280 observatories worldwide at a number of time resolutions are held along with various magnetic survey, model, and activity index data. The operation of this data centre provides a valuable resource for the geomagnetic research community. The operation of the WDC and details of the range of data held are presented. The quality control procedures that are applied to incoming data are described as is the work to collaborate with other data centres to distribute and improve the overall consistency of data held worldwide. The development of standards for metadata associated with datasets is demonstrated, and current efforts to digitally preserve the BGS analogue holdings of magnetograms and observatory yearbooks are described.

  • the 10th generation international geomagnetic reference field
    Physics of the Earth and Planetary Interiors, 2005
    Co-Authors: Stefan Maus, Susan Macmillan, T Chernova, S Choi, D Dater, V Golovkov, Vincent Lesur, F Lowes, H Luhr, W Mai
    Abstract:

    Abstract The International Association of Geomagnetism and Aeronomy (IAGA) on 12 December 2004 released the 10th generation International Geomagnetic Reference Field (IGRF)—the latest version of a standard mathematical description of the Earth's main magnetic field and used widely in studies of the Earth's deep interior, its crust, ionosphere and magnetosphere. The coefficients were finalised by a task force of IAGA. The IGRF is the product of a large collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and observatories around the world.

  • the 9th generation international geomagnetic reference field
    Geophysical Journal International, 2003
    Co-Authors: Susan Macmillan, Stefan Maus, V Golovkov, Vincent Lesur, T Bondar, A Chambodut, Richard Holme, B Langlais, F J Lowes, H Luhr
    Abstract:

    SUMMARY The International Association of Geomagnetism and Aeronomy has recently released the 9th-Generation International Geomagnetic Reference Field—the latest version of a standard mathematical description of the Earth's main magnetic field used widely in studies of the Earth's deep interior, its crust and its ionosphere and magnetosphere. The coefficients were recently finalized at the XXIII General Assembly of the International Union of Geophysics and Geodesy, held at Sapporo in Japan in 2003 July. The IGRF is the product of a huge collaborative effort between magnetic field modellers and the institutes involved in collecting and disseminating magnetic field data from satellites and from observatories and surveys around the world.

  • international geomagnetic reference field the eighth generation
    Earth Planets and Space, 2000
    Co-Authors: M Mandea, Susan Macmillan
    Abstract:

    The eighth generation of the International Geomagnetic Reference Field (IGRF) was adopted in 1999 by the International Association of Geomagnetism and Aeronomy (IAGA) Division V, Working Group 8. This differs from the previous generation by the addition of the IGRF 2000 which comprises a main-field model for the epoch 2000.0 and a predictive secular-variation model for 2000.0–2005.0. This paper lists the IGRF coefficients and includes contour maps computed using IGRF 2000.

Kang G Shin - One of the best experts on this subject based on the ideXlab platform.

  • Geomagnetism for smartphone based indoor localization challenges advances and comparisons
    ACM Computing Surveys, 2017
    Co-Authors: Kang G Shin
    Abstract:

    Geomagnetism has recently attracted considerable attention for indoor localization due to its pervasiveness and independence from extra infrastructure. Its location signature has been observed to be temporally stable and spatially discernible for localization purposes. This survey examines and analyzes the recent challenges and advances in Geomagnetism-based indoor localization using smartphones. We first study smartphone-based Geomagnetism measurements. We then review recent efforts in database construction and computation reduction, followed by state-of-the-art schemes in localizing the target. For each category, we identify practical deployment challenges and compare related studies. Finally, we summarize future directions and provide a guideline for new researchers in this field.

Jun Luo - One of the best experts on this subject based on the ideXlab platform.

  • groping Geomagnetism and crowdsensing powered indoor navigation
    IEEE Transactions on Mobile Computing, 2015
    Co-Authors: Chi Zhang, Kalyan Pathapati Subbu, Jun Luo
    Abstract:

    Although a large number of WiFi fingerprinting based indoor localization systems have been proposed, our field experience with Google Maps Indoor (GMI), the only system available for public testing, shows that it is far from mature for indoor navigation. In this paper, we first report our field studies with GMI, as well as experiment results aiming to explain our unsatisfactory GMI experience. Then motivated by the obtained insights, we propose GROPING as a self-contained indoor navigation system independent of any infrastructural support. GROPING relies on geomagnetic fingerprints that are far more stable than WiFi fingerprints, and it exploits crowdsensing to construct floor maps rather than expecting individual venues to supply digitized maps. Based on our experiments with 20 participants in various floors of a big shopping mall, GROPING is able to deliver a sufficient accuracy for localization and thus provides smooth navigation experience.

Menggang Chen - One of the best experts on this subject based on the ideXlab platform.

  • Geomagnetism based indoor navigation by offloading strategy in nb iot
    IEEE Internet of Things Journal, 2019
    Co-Authors: Dongzhuo Liu, Songtao Guo, Yuanyuan Yang, Yawei Shi, Menggang Chen
    Abstract:

    Most indoor navigation technologies need to provide structure maps of buildings, but it is difficult to obtain these structure maps in practice. Therefore, we design a Geomagnetism-based indoor navigation system without structure map of buildings by applying offloading strategy in narrow band Internet of Things. Why the geomagnetic signal can be used to achieve indoor navigation is due to its stability. We divide the indoor navigation into two parts: 1) the construction of signal fingerprint database and 2) the user navigation. First, the navigator carries out the signal acquisition of navigation route, and transfers the original signals to cloud server so as to construct the fingerprint database. Second, users can choose online navigation or offline navigation according to the actual situation. When choosing offline navigation, the users will employ dynamic time warping algorithm for fingerprint matching. When users would like to obtain better navigation results, they can choose online navigation. In this case, navigation system will offload the users’ sampling data to remote cloud, and then the cloud matches the fingerprint of geomagnetic signals by using particle filter algorithm and sends the computation results to the users so as to indicate the users’ moving direction. Experiment results demonstrate that our method is effective and the turning error is only 5 cm.

Yoshichika ōnuki - One of the best experts on this subject based on the ideXlab platform.

  • effect of Geomagnetism on 101ru nuclear quadrupole resonance measurements of ceru2
    Journal of the Physical Society of Japan, 2015
    Co-Authors: Masahiro Manago, Kenji Ishida, Tatsuma D Matsuda, Yoshichika ōnuki
    Abstract:

    We performed 101Ru nuclear quadrupole resonance (NQR) measurements on the s-wave superconductor CeRu2 and found oscillatory behavior in the spin-echo amplitude at the \(| {\pm} 1/2\rangle \leftrightarrow | {\pm} 3/2\rangle \) transitions but not at the \(| {\pm} 3/2\rangle \leftrightarrow | {\pm} 5/2\rangle \) transitions. The modulation disappears in the superconducting state or in a magnetic shield, which implies a geomagnetic field effect. Our results indicate that the NQR spin-echo decay curve at the \(| {\pm} 1/2\rangle \leftrightarrow | {\pm} 3/2\rangle \) transitions is sensitive to a weak magnetic field.

  • effect of Geomagnetism on 101ru nuclear quadrupole resonance measurements of ceru2
    arXiv: Superconductivity, 2015
    Co-Authors: Masahiro Manago, Kenji Ishida, Tatsuma D Matsuda, Yoshichika ōnuki
    Abstract:

    We performed 101Ru nuclear quadrupole resonance (NQR) measurements on the s-wave superconductor CeRu2 and found oscillatory behavior in the spin-echo amplitude at the +-1/2 +-3/2 transitions but not at the +-3/2 +-5/2 transitions. The modulation disappears in the superconducting state or in a magnetic shield, which implies a geomagnetic field effect. Our results indicate that the NQR spin-echo decay curve at the +-1/2 +-3/2 transitions is sensitive to a weak magnetic field.