09:00 〜 09:15
[SGD01-11] 2023年度下里水路観測所SLR/GNSSコロケーション測量
キーワード：SLR、GNSS、コロケーション、ローカルタイ
The Japan Coast Guard (JCG) operates Satellite Laser Ranging (SLR) observation at the Shimosato Hydrographic Observatory (SHO) since 1982 to link the origin of nautical charts to the global geodetic reference frame. We have also been conducting GNSS observation at SHO since 2004. The SLR and GNSS sites in SHO are registered to the International Laser Ranging Service (ILRS) as “7838” and to the International GNSS Service (IGS) as “SMST”, respectively. Currently, SHO is operating these two types of space geodetic techniques, and can be defined as a co-location site of SLR and GNSS.
Co-location sites, which operate multiple space geodetic techniques like the SHO, are necessary to link the four space geodetic techniques used in the International Terrestrial Reference Frame (ITRF); SLR, GNSS, Very Long Baseline Interferometry (VLBI), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). The accuracy of the ITRF is affected by the quantity and the precision of the local ties (the relative positions) between the different space geodetic techniques at the co-location sites. The International Earth Rotation System (IERS) recommends to measure the local ties in the precision of sub-millimeters, which can be achieved by precisely conducting a local tie survey.
In November 2020, JCG and the Geospatial Information Authority of Japan (GSI), which has a prolonged experience of local tie surveys at their VLBI/GNSS co-location sites, have performed a local tie survey at the SHO to determine the local tie between the invariant point of the SLR telescope and the GNSS station. The local tie was determined by a precision of few millimeters, and the survey result was submitted to the IERS for the calculation of ITRF2020. Since then, JCG has conducted local tie surveys in March 2023 and November 2023, to monitor the local tie and to prepare for the future versions of the ITRF. In this presentation, we will present the procedures of our local tie survey, and discuss on the result of our latest survey conducted in November 2023 by comparing with the results of the previous surveys.
Acknowledgements: We thank the staffs of the Geospatial Information Authority for technical support and providing us survey instruments. We also thank Prof. Otsubo of the Hitotsubashi University and Dr. Kouno of the University of Tokyo for providing us survey instruments. Finally, we thank the staffs of the JCG and SHO for supporting this survey.
Co-location sites, which operate multiple space geodetic techniques like the SHO, are necessary to link the four space geodetic techniques used in the International Terrestrial Reference Frame (ITRF); SLR, GNSS, Very Long Baseline Interferometry (VLBI), and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). The accuracy of the ITRF is affected by the quantity and the precision of the local ties (the relative positions) between the different space geodetic techniques at the co-location sites. The International Earth Rotation System (IERS) recommends to measure the local ties in the precision of sub-millimeters, which can be achieved by precisely conducting a local tie survey.
In November 2020, JCG and the Geospatial Information Authority of Japan (GSI), which has a prolonged experience of local tie surveys at their VLBI/GNSS co-location sites, have performed a local tie survey at the SHO to determine the local tie between the invariant point of the SLR telescope and the GNSS station. The local tie was determined by a precision of few millimeters, and the survey result was submitted to the IERS for the calculation of ITRF2020. Since then, JCG has conducted local tie surveys in March 2023 and November 2023, to monitor the local tie and to prepare for the future versions of the ITRF. In this presentation, we will present the procedures of our local tie survey, and discuss on the result of our latest survey conducted in November 2023 by comparing with the results of the previous surveys.
Acknowledgements: We thank the staffs of the Geospatial Information Authority for technical support and providing us survey instruments. We also thank Prof. Otsubo of the Hitotsubashi University and Dr. Kouno of the University of Tokyo for providing us survey instruments. Finally, we thank the staffs of the JCG and SHO for supporting this survey.