[S-GD02] Geodesy and Global Geodetic Observing System

[SGD02-P09] Accuracy evaluation of GNSS-A observation using GARPOS: seafloor station array and vertical position

*Yusuke Yokota¹, Tadashi Ishikawa², Shun-ichi Watanabe², Yuto Nakamura² (1.Institute of Industrial Science, The University of Tokyo, 2.Hydrographic and Oceanographic Department, Japan Coast Guard)

Keywords:GNSS-A, Seafloor geodesy

In GNSS-A, seafloor acoustic stations are observed from the sea surface station such as vessels. In SGO-A operated by the Japan Coast Guard, the vessels observe while moving. GARPOS, which has been developed in Watanabe et al. [2020], determines the positions of the seafloor stations with high accuracy by estimating the disturbance in the sea water. At this time, the observation data are analyzed by constraining the array shapes of seafloor stations, but if the array shape was distorted, the results are adversely affected. In general, it is difficult to detect the distortion of the seafloor station array, but it has been found that it may be possible to detect it from the anomaly of the undersea disturbance obtained by GARPOS.
In GNSS-A, it has been considered difficult to accurately determine the vertical position due to the influence of the observation arrangement. However, recent studies have revealed that the effect of distortion in the vertical position occurs as an error in the actual data in proportion to the angle with respect to the seafloor station. From this, it was found that there is a possibility that the error of the vertical position can be reduced.
In this presentation, we report on the recent development of accuracy evaluation method of GNSS-A.

Acknowledgement: This study was supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, under its The Second Earthquake and Volcano Hazards Observation and Research Program (Earthquake and Volcano Hazard Reduction Research).