Article
Remote Sensing
Rui Wang, Doris Becker, Thomas Hobiger
Summary: To improve the centimeter-level positioning accuracy of real-time kinematic (RTK), an enhanced Kalman filtering procedure is proposed in this study. By adaptively estimating the variance-covariance matrix of double-differenced measurements based on a posteriori residuals, instead of approximating it by an empirical function using satellite elevation angle, the success rate of ambiguity resolution and the reliability of positioning results are enhanced. Moreover, a stochastic model based on robust Kalman filtering is introduced to compute the variance-covariance matrix of double-differenced measurement noise empirically, using a modified version of the IGG III method, for outlier detection and identification, improving the filter performance.
Article
Oceanography
Daniel Giles, Audrey Gailler, Frederic Dias
Summary: This study investigates how to capture the spatial variability of an incoming tsunami and proposes two alternative methods: transfer functions and machine learning techniques. The transfer function is based on an extension of Green's Law that introduces local amplification parameters. A machine learning model is trained to predict the localized tsunami hazard. These methods aid in providing high-resolution tsunami warnings.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Article
Computer Science, Artificial Intelligence
Seonghyeon Park, Seokhoon Ryu, Jihea Lim, Young-Sup Lee
Summary: This study examines the feasibility of using a low-cost real-time kinematic GPS sensor for localization of an autonomous vehicle to achieve high-speed driving. By utilizing the RTK-GPS position to reduce errors and implementing a modified pure pursuit algorithm, the test vehicle was able to complete a lap on a racing track at 130 kph without departures from the track or noticeable errors, albeit 32 seconds slower than the record set by a professional human driver.
JOURNAL OF REAL-TIME IMAGE PROCESSING
(2021)
Article
Engineering, Marine
Yukiharu Hisaki
Summary: The study suggests that drifting buoy wave data can serve as valuable reference data for ocean forecasting, showing good agreement with data observed by moored GPS buoys, especially in areas with strong currents.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Aerospace
Prasert Kenpankho, Amornchai Chaichana, Koson Trachu, Pornchai Supnithi, Kornyanat Hozumi
Summary: This paper presents a new method for real-time GPS receiver bias estimation using Lagrange interpolation, compared with polynomial and minimization of standard deviation methods. The results show that Lagrange interpolation can reduce the complexity and time for GPS receiver bias estimation, providing more time points for finding biases compared to other methods.
ADVANCES IN SPACE RESEARCH
(2021)
Article
Engineering, Civil
Chengxin Luo, Wei Ding, Chi Zhang, Xuan Yang
Summary: To effectively mitigate droughts, multiple hydrological forecasts are needed. This study proposes a novel Model Predictive Control (MPC) that integrates streamflow forecast, regime state forecast, and annual streamflow volume state forecast. By incorporating these forecasts, significant performance gains can be achieved in drought mitigation. However, forecast value is influenced by forecast uncertainty and other factors.
JOURNAL OF HYDROLOGY
(2023)
Article
Engineering, Aerospace
Kan Wang, Baoqi Sun, Weijin Qin, Xiaolong Mi, Ahmed El-Mowafy, Xuhai Yang
Summary: Long-baseline time transfer can achieve high frequency stability through post-processed batch least-squares adjustment using PPP or IPPP methods. Real-time PPP users experience degraded time transfer results due to filter-based processing and lower accuracy of real-time satellite orbits and clocks. The PPP-RTK technique combines the advantages of PPP and RTK methods, allowing for real-time long-baseline time transfer without relying on external high-sampling and high-precision satellite clocks.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Computer Science, Information Systems
Zun Niu, Fugui Guo, Qiangqiang Shuai, Guangchen Li, Bocheng Zhu
Summary: RTK and VIO are promising positioning technologies but have limitations in certain environments. Integrating them on smartphones can improve accuracy and robustness, with potential applications in navigation and positioning research.
ISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION
(2021)
Article
Remote Sensing
Yang Liu, Menghao Li, Yanxiong Liu, Yanfeng Wang, Shumin Jiang, Yabin Wang, Li Tian, Fangli Qiao
Summary: In this study, a global real-time low-cost centimeter-level precise wave measurement method using onboard GNSS variometric velocities and segment wave parameter retrievals is proposed. The method outperforms the Doppler approach in terms of velocity accuracy and displacement determination, and it can achieve real-time precise wave measurement at remarkably low costs.
INTERNATIONAL JOURNAL OF APPLIED EARTH OBSERVATION AND GEOINFORMATION
(2022)
Article
Engineering, Electrical & Electronic
Rui Tu, Pengfei Zhang, Rui Zhang, Lihong Fan, Junqiang Han, Ju Hong, Jinhai Liu, Xiaochun Lu
Summary: The study proposes a real-time and dynamic time transfer method based on double-differenced (DD) GNSS observations, which fixes ambiguities and achieves time transfer using single-differenced (SD) observations. Validation results demonstrate that the method provides better accuracy and stability for positioning and time transfers compared to undifferenced methods, making it more suitable for real-time applications.
IET RADAR SONAR AND NAVIGATION
(2021)
Article
Engineering, Electrical & Electronic
Risto Ojala, Jari Vepsalainen, Jesse Pirhonen, Kari Tammi
Summary: Intelligent transportation and smart city applications are growing rapidly, and accurate sensor perception of vehicles is crucial. This paper proposes an automated calibration approach for partially connected vehicle environments, utilizing Global Navigation Satellite System positioning information to fit a direct transformation between image and ground plane coordinates. Experimental results show that the camera-based localization accuracy is adequate for many intelligent transportation applications.
IET INTELLIGENT TRANSPORT SYSTEMS
(2023)
Article
Geochemistry & Geophysics
Xiao Yin, Hongzhou Chai, Wenbing Xu, Liang Zhao, Huawei Zhu
Summary: Real-time kinematic (RTK) technology is widely used for high-precision positioning in the offshore area. However, its mass-market applications are limited due to the need for bi-directional communication and error grouping. PPP-RTK, combining precise point positioning (PPP) and RTK, has become a hotspot technology in the mass market. In this contribution, an uncombined multi-GNSS PPP-RTK model is proposed, using uncalibrated phase delays estimated from legacy ionosphere-free and Melbourne-Wubbena combination. By conducting PPP ambiguity resolution (AR) and deriving precise atmospheric corrections, the positioning accuracy in the offshore area can be improved to a level similar to RTK.
Article
Geosciences, Multidisciplinary
Daniel Giles, Devaraj Gopinathan, Serge Guillas, Frederic Dias
Summary: Tsunamis are unpredictable and pose challenges to the tsunami community. Accurate mathematical/computational modeling is needed for tsunami forecasts and hazard assessments. Warning centres face challenges in delivering accurate forecasts under severe time constraints due to the physical nature of tsunamis.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Environmental Sciences
Yineng Li, Shaotian Li, Shiqiu Peng, Yuhang Zhu, Fenghua Zhou, Shilin Tang
Summary: This study introduces an updated version of the real-time Experimental Platform of Marine Environment Forecasting system for the North Indian Ocean, called EPMEF-NIO. The updates include adding the western Indian Ocean to the regions for weather, surge, and wave forecasts, increasing the horizontal resolutions for the two-domain weather forecast, adding a three-domain-nested wave forecast, and extending the length of the forecast time. The assessment based on substantial observations shows that the EPMEF-NIO performs well in weather, wave, and storm surge forecasts, thanks to the spectacular techniques employed in the system.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Robotics
Kento Fukuda, Shin Kawai, Hajime Nobuhara
Summary: In this study, a connected multiple drone system using electromagnets is designed, and an attitude estimation method based on an extended Kalman filter and multiple GPS is proposed to replace magnetic sensors. Experimental results demonstrate that the proposed method achieves higher accuracy and stability in attitude estimation compared to conventional methods in both simulation and real environments.
Article
Geosciences, Multidisciplinary
Yutaka Hayashi, Hiroaki Tsushima, Kenji Hirata, Kazuhiro Kimura, Kenji Maeda
EARTH PLANETS AND SPACE
(2011)
Article
Geosciences, Multidisciplinary
Hiroaki Tsushima, Kenji Hirata, Yutaka Hayashi, Yuichiro Tanioka, Kazuhiro Kimura, Shin'ichi Sakai, Masanao Shinohara, Toshihiko Kanazawa, Ryota Hino, Kenji Maeda
EARTH PLANETS AND SPACE
(2011)
Article
Geochemistry & Geophysics
Yutaka Hayashi, Shunichi Koshimura, Fumihiko Imamura
GEOPHYSICAL JOURNAL INTERNATIONAL
(2012)
Article
Geosciences, Multidisciplinary
S. Koshimura, Y. Hayashi, K. Munemoto, F. Imamura
GEOPHYSICAL RESEARCH LETTERS
(2008)
Article
Geosciences, Multidisciplinary
Yoshihiro Ito, Takeshi Tsuji, Yukihito Osada, Motoyuki Kido, Daisuke Inazu, Yutaka Hayashi, Hiroaki Tsushima, Ryota Hino, Hiromi Fujimoto
GEOPHYSICAL RESEARCH LETTERS
(2011)
Article
Oceanography
Y. Hayashi
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2008)
Article
Geosciences, Multidisciplinary
Kenji Nakata, Yutaka Hayashi, Hiroaki Tsushima, Kenichi Fujita, Yasuhiro Yoshida, Akio Katsumata
EARTH PLANETS AND SPACE
(2019)
Article
Geochemistry & Geophysics
Yutaka Hayashi
Summary: The oldest historical tsunami record in Central America from 1537 is considered doubtful as it lacks confirmation from authorities outside Japan. Research reveals the source of this suspicion to be a miscopying of data. Failure to add the correct information during compilation led to the erroneous report of the 1537 Mexican earthquake tsunami.
SEISMOLOGICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Akio Katsumata, Yutaka Hayashi, Kazuki Miyaoka, Hiroaki Tsushima, Toshitaka Baba, Patricio A. Catalan, Cecilia Zelaya, Felipe Riquelme Vasquez, Rodrigo Sanchez-Olavarria, Sergio Barrientos
NATURAL HAZARDS AND EARTH SYSTEM SCIENCES
(2017)
Article
Geosciences, Multidisciplinary
T Yamawaki, S Tanaka, S Ueki, H Hamaguchi, H Nakamichi, T Nishimura, J Oikawa, T Tsutsui, K Nishi, H Shimizu, S Yamaguchi, H Miyamachi, H Yamasato, Y Hayashi
JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH
(2004)
Article
Geosciences, Multidisciplinary
Yutaka Hayashi, Kenji Hirata, Tsurane Kuragano, Toshiyuki Sakurai, Hiromi Takayama, Yohei Hasegawa, Nobuo Hamada
EARTH PLANETS AND SPACE
(2007)
Article
Geosciences, Multidisciplinary
K Hirata, K Satake, Y Tanioka, T Kuragano, Y Hasegawa, Y Hayashi, N Hamada
EARTH PLANETS AND SPACE
(2006)
Article
Geosciences, Multidisciplinary
Y Tanioka, Y Nishimura, K Hirakawa, F Imamura, I Abe, Y Abe, K Shindou, H Matsutomi, T Takahashi, K Imai, K Harada, Y Namegawa, Y Hasegawa, Y Hayashi, F Nanayama, T Kamataki, Y Kawata, Y Fukasawa, S Koshimura, Y Hada, Y Azumai, K Hirata, A Kamikawa, A Yoshikawa, T Shiga, M Kobayashi, S Masaka
EARTH PLANETS AND SPACE
(2004)
