ACCURATE DETERMINATION OF CALIBRATION FACTOR OF gPhone SPRING GRAVIMETERS BY USING M2 TIDAL WAVE AMPLITUDE FACTOR
Liu Ziwei 1,2) ;Li Hui 1) ;Wei Jin 1,3) ;Hao Hongtao 1) ; and Wu Yunlong 1)
1)Institute of Seismology,CEA,Wuhan 4300712)School of Computer Science,Wuhan University,Wuhan 4300793)School of Geodesy and Geomatics,Wuhan University,Wuhan 430079
Abstract：The newest generation of gPhone spring gravimeter of Microg LaCoste Inc. is the major observation instrument of China earthquake monitoring network. In this paper, We use M2 tidal wave amplitude factor from the tidal analysis from long period observation data of SGC053 superconducting gravimeter to determinate the calibration factor of 28 colocated gPhone spring gravimeters which passed the test at the some place. The results show that the calibration factor of these instruments are between 0.999 9 and 1.019 6, and that the calibration factor of instrument had been determined before they leave the factory but now is subtlely changing because of new observation location. We analyzed and processed the observation data after correction again. The precision of M2 tidal wave factors are better than 0.8‰, the non tidal gravity change in time series of residual with drift correction is (4-10)×10 -8 ms -2, amplitude of diurnal wave is less than 0.1×10 -8 ms -2, and amplitude of semidiurnal wave is less than 0.3×10 -8 ms -2, so it is proved that the results are well improved after determination. It is indicated that gPhone spring gravimeters can be used for the observation under a unified tidal datum by using precise M2 tidal wave factor to determinate the calibration factor of instrument, further it can provide accurate observation data of gravity change for earthquake monitoring by gravity and scientific research.
Liu Ziwei,Li Hui ,Wei Jin et al. ACCURATE DETERMINATION OF CALIBRATION FACTOR OF gPhone SPRING GRAVIMETERS BY USING M2 TIDAL WAVE AMPLITUDE FACTOR[J]. jgg, 2011, 31(5): 146-150.
