A5101461465- Indoor and Outdoor Localization Technologies
- GNSS positioning and interference
- Vehicular Ad Hoc Networks (VANETs)
- Millimeter-Wave Propagation and Modeling
- Inertial Sensor and Navigation
- Internet of Things and Social Network Interactions
- 3D Modeling in Geospatial Applications
- Geophysics and Gravity Measurements
- Geological Modeling and Analysis
- Control and Dynamics of Mobile Robots
- Robotic Locomotion and Control
- Radio Wave Propagation Studies
- 3D Surveying and Cultural Heritage
- IoT and GPS-based Vehicle Safety Systems
- Satellite Image Processing and Photogrammetry
- Remote Sensing and LiDAR Applications
National Institute of Information and Communications Technology
2024
Tokyo University of Marine Science and Technology
2018-2020
Keihin (Japan)
2019-2020
Advanced Telecommunications Research Institute International
2013-2014
The reduction of multipath errors is a significant challenge in the Global Navigation Satellite System (GNSS), especially when receiving non-line-of-sight (NLOS) signals. However, selecting line-of-sight (LOS) satellites correctly still difficult task dense urban areas, even with latest GNSS receivers. This study demonstrates new method utilization C/N0 to detect NLOS elevation-dependent threshold setting may be effective mitigating errors. fluctuation affected by signals quite large. If...
To utilize RTK-GNSS in urban areas, it is important to predict areas which can be used. The performance of RTKGNSS depends on the geometry and number visible satellites signal quality. These parameters potentially predicted using simulations that consider relative between receiver surrounding objects. In this study, we first verified whether GNSS quality correctly 3D models buildings measurement data. Subsequently, FIX status RTK predicted. results show measured have good was agreement at...
To simulate radio propagation in a dynamic indoor environment such as factory operating with moving people and automated guided vehicles (AGV), we devised technique to determine shielding losses by objects based on ray tracing. For object environment, conventional ray-tracing methods require simulation of each snapshot object. This requires too much time for real-time predictions. The proposed method first calculates the static using without object, then loss caused is included through...
The reflections and diffractions of global navigation satellite system (GNSS) signals from buildings may produce large measurement errors. Detecting non-line-of-sight using 3D maps is a means to detect exclude satellites with However, the true position typically needed for maps. In this study, we verify assumption that an approximate user can be used when We found correct fixed real-time kinematic GNSS (RTK-GNSS) could achieved positions RTK-GNSS assisted by were within 5-15m position.
Support system for safe driving heavily depends on global navigation satellite system. Pseudoranges between satellites and vehicles are measured to compute vehicles’ positions their relative positions. In urban areas, however, multipath errors (MPEs) in pseudoranges, caused by obstruction reflection of roadside buildings, greatly degrade the precision On other hand, simply removing all reflected signals might lead a shortage fixing our previous work, we suggested solving this dilemma...
衛星測位のRTK-GNSSなどの高精度測位におけるFIX解の算出状況は,実施地点における衛星配置,衛星数,観測情報の品質と測位アルゴリズムに依存する.衛星配置は航法メッセージにより推定することが可能であり,可視衛星数と観測情報の品質は,周辺の建物などによる信号の遮蔽,反射およびアンテナ・受信機の性能を考慮し,シミュレーションにより推定することが可能である.本研究では衛星測位における観測情報の品質を,3D建物モデルを用いたシミュレーションにより予測し,実際の観測情報との比較を行った.また,高精度測位を実施した結果と比較し,シミュレーションによるRTK-GNSS測位のFIX状況予測の可能性を検討した.
In this study, actual measurement data in an urban area was obtained, and a simulation using 3D maps implemented. A high precision positional system equipped on vehicle order to collect measurements at each time. The obtained by the used as reference coordinate for both measurements. Consequently, comparison between satellite visibility implemented first dominant deterioration factor of accuracy is Non-line-of-sight (NLoS) signals caused reflection or diffraction from buildings. If our tells...
As a simple method to simulate dynamic indoor environment, we investigated calculate the shielding effect of moving objects. In this method, is included in post-processing on results ray tracing calculations that does not include The time depends numbers ray-traced paths. We applied path clustering for paths advance reduce time. result, calculation propagation environment reduced compared against conventional tracing.
Position information plays an important role in support system for safe driving, where inter-vehicle distance is used to prevent collision accidents from happening. In urban areas, however, multipath propagation of GPS signals degrades the accuracy absolute positions and deduced relative position. On other hand, simply removing reflected might lead a shortage satellites fixing positions. our previous work, we suggested cooperative positioning improve adjacent vehicles so as this paper, focus...