Japan Geoscience Union Meeting 2023

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S (Solid Earth Sciences ) » S-CG Complex & General

[S-CG53] Reducing risks from earthquakes, tsunamis & volcanoes: new applications of realtime geophysical data

Wed. May 24, 2023 10:45 AM - 12:15 PM Online Poster Zoom Room (16) (Online Poster)

convener:Masashi Ogiso(Meteorological Research Institute, Japan Meteorological Agency), Masumi Yamada(Disaster Prevention Research Institute, Kyoto University), Yusaku Ohta(Research Center for Prediction of Earthquakes and Volcanic Eruptions, Graduate School of Science, Tohoku University), Naotaka YAMAMOTO CHIKASADA(National Research Institute for Earth Science and Disaster Resilience)

On-site poster schedule(2023/5/23 17:15-18:45)

10:45 AM - 12:15 PM

[SCG53-P01] Improving the real-time GNSS positioning technique for better understanding of crustal deformation

*Takamatsu Naofumi1, Takayuki Miyazaki1, Satoshi Abe1, Keitaro Ohno1, Shinsuke Murakami1, Yoshiki Takei1, Satoshi Kawamoto1 (1.Geospatial Information Authority of Japan)

Keywords:GNSS, GEONET, REGARD, relative positioning, PPP, multi-GNSS

Geospatial Information Authority of Japan (GSI) has been operating the REGARD system since 2016, which estimates finite fault models in real-time using GNSS data observed by GEONET, and has contributed to initial response at the government agencies in an earthquake. In order to enhance the reliability of REGARD in preparation for a gigantic earthquake along the Nankai Trough, which is expected to cause extensive damage, it is essential to improve the accuracy of the real-time GNSS positioning solutions that serve as input for fault estimation. Currently, REGARD employs a positioning method that determines relative positions across Japan using fixed stations on the Sea of Japan side, where the impact of a huge subduction zone earthquake is relatively small. However, if noise originating from a fixed station is generated, it spreads to all stations and adversely affects the positioning solution. In addition, REGARD uses GPS and GLONASS as GNSS satellites, but it is also necessary to deal with Japan’s QZSS, which is scheduled to reach a total of seven satellites by FY2023. Based on these, GSI is aiming to improve the accuracy of positioning solutions by using Precise Point Positioning (PPP) with multi-GNSS. PPP does not require a fixed station and thus the coordinates of each station are obtained independently, which makes solution not being degraded by a fixed station. The satellite orbit/clock information and correction information required for PPP are planned to be obtained by using the Japan Aerospace Exploration Agency (JAXA)-developed MADOCA for high-precision orbit determination. In our presentation, we will report preliminary positioning results for both relative positioning and PPP.