Best Paper Award

Displacement and Vibration Monitoring by GB-SAR[IEICE TRANS. COMMUN., Vol.J102-B, No.11 NOVEMBER 2019]

Motoyuki SATO
Motoyuki SATO
Lilong ZOU
Lilong ZOU
Giovanni NICO
Giovanni NICO
Kazutaka KIKUTA
Kazutaka KIKUTA

Natural disasters, including the Great East Japan Earthquake, the Kumamoto Earthquake, and landslides and floods caused by heavy rain, often happen in Japan. We expect Volcanic activity, and a Nankai Trough Earthquake which are inevitable at some point. Sensors such as inclinometers, strain meters or GNSS have been used for landslide monitoring, but these sensors can only monitor discrete positions, and installation of the sensor requires an accurate prediction of the position of displacement beforehand.

The Ground Based Synthetic Aperture Radar (GB-SAR) introduced in this paper is a radar system to be fixed on the ground which can continuously measure an area of several square kilometers from a location more than 1km away. Furthermore, using the interference SAR method, we can estimate the displacement of the ground surface with 1 mm accuracy in real time and with a spatial resolution of several meters. GB-SAR has been put into practical use in the last 10 years.

After explaining the development and technical features of GB-SAR, the authors describe the atmospheric correction method required for the high-precision measurement of ground surface displacement and propose the use of radar polarimetry and multiple-frequency to obtain more advanced ground surface information. In addition, while the current GB-SAR system moves the radar transceiver device on a fixed rail to acquire data, the next generation system, namely MIMO GB-SAR is introduced, which uses multiple fixed transmitter / receiver antennas. MIMO GB-SAR has excellent environmental resistance, and the authors demonstrated its performance.

Based on basic research on GB-SAR equipment, this paper shows the social implementation of long-term landslide monitoring in Miyagi and Kumamoto prefectures and its effectiveness, which was conducted by the authors. Furthermore, it demonstrates the possibility of continuous monitoring of social infrastructure such as bridges, dams, and airport pavement surfaces. It is expected that the utilization of GB-SAR technology in society will greatly contribute to the construction of a resilient society, not limited to disaster prevention and mitigation in Japan. For the above reasons, this paper can be highly evaluated as a paper worthy of this award.