TERRAPUB Earth, Planets and Space

Earth Planets Space, Vol. 52 (No. 10), pp. 881-884, 2000

LETTER

GPS seismometers with up to 20 Hz sampling rate

Linlin Ge1, Shaowei Han1, Chris Rizos1, Yuzo Ishikawa2, Mitsuyuki Hoshiba2, Yasuhiro Yoshida2, Mitsuma Izawa3, Narihiro Hashimoto4, and Shigeru Himori5

1School of Geomatic Engineering, The University of New South Wales, Sydney, Australia
2Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan
3Trimble Japan, Japan
4Hitachi Zosen Information Systems Co. Ltd., Japan
5Katsujima Co. Ltd., Japan

(Received January 6, 2000; Revised May 18, 2000; Accepted May 31, 2000)

Abstract: The large near-field displacements before and during an earthquake are invaluable information for earthquake source study and for the detection of slow/silent quakes or pre-seismic crustal deformation events. However due to bandwidth limitations and saturation current seismometers cannot measure many of these displacements directly. In a joint experiment between the University of New South Wales (UNSW) and the Meteorological Research Institute (MRI), two Trimble MS750 GPS receivers were used in the Real-Time Kinematic (RTK) mode with a fast sampling rate of up to 20 Hz to test the feasibility of a "GPS seismometer" in measuring displacements directly. The GPS antenna, an accelerometer, and a velocimeter were installed on the roof of an earthquake shake-simulator truck. The simulated seismic waveforms resolved from the RTK time series are in very good agreement with the results from the accelerometer and the velocimeter, after integrating twice and once respectively. Moreover, more displacement information are revealed in the GPS RTK results although they are noisier.


Corresponding author E-mail: l.ge@student.unsw.edu.au


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