Monitoring of Land Deformation in Kanagawa Prefecture Using GNSS and C-band Sentinel-1 Based Consecutive DInSAR

Abstract

In Japan, precipitation has recently become more localized, concentrated, and intense. Extreme precipitation has caused a rapid land deformation, which results in ground water levels and loss of building stability. For the appropriate maintenance and renewal of infrastructure, including the design method of underground structures, the utilization of remote sensing technology which can always observe the ground deformation over a wide range with high accuracy is expected. This research presents the results of long-term continuous land deformation (subsidence or uplift) monitoring and using Global Navigation Satellite System (GNSS) and Consecutive Differential Interferometric Synthetic Aperture Radar (DInSAR) technique in Yokohama, Yokosuka and Miura cities, Kanagawa Prefecture, Japan. We adopted the Consecutive DInSAR method with the small spatial and short time baseline between satellites. The satellite data used thirty-three pairs of Sentinel-1 data in descending orbit from December 27, 2017 to November 17, 2020, and twenty-two Sentinel-1 data pairs in ascending orbit from June 26, 2019 to October 30, 2020. The validation of the SAR images used the daily coordinate values of the GNSS control point provided by the Geographical Survey Institute (GSI). As a result of the analysis, the estimated land displacement and GNSS data agreed well in Yokohama, Yokosuka, and Miura cities. The RMSE in descending orbit of Yokohama, Yokosuka and Miura cities were found to be 0.41 cm, 0.49 cm, and 0.49 cm, respectively and the RMSE in ascending orbit of Yokohama, Yokosuka and Miura cities were found to be 0.68 cm, 0.53 cm, and 0.58 cm, respectively, demonstrating its capability to analyze the land displacement monitoring over under different topographical conditions. In the future, this research result is expected to applicable in the field of disaster monitoring and environmental change observation which continuously require high accuracy observation over a wide area.