利用M2潮波振幅因子精密测定gPhone弹簧重力仪的标定因子

摘要

The newest generation of gPhone spring gravimeter of Micro-g 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 SC-C053 superconducting gravimeter to determinate the calibration factor of 28 co-located 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) xl0-8ms-2, amplitude of diurnal wave is less than 0. 1x10-8 ms-2, and amplitude of semidiurnal wave is less than 0.3 x 10-8ms-2, so it is proved that the results are well improved after determination. It is indicated thatgPhone spring gravimeters can be used for the observation under a unified tidal datum by using precise M2 tidalwave factor to determinate the calibration factor of instrument, further it can provide accurate observation data ofgravity change for earthquake monitoring by gravity and scientific research.%用SG-C053超导重力仪长时间观测数据潮汐分析结果中的M2潮波振幅因子,对同址观测的28台gPhone重力仪标定因子进行了精密测定,结果表明,28台仪器标定因子的变化范围为0.9999～1.019 6,反应出仪器的标定因子在出厂前已经过测定,但在新的观测位置产生了微小的变化.对经过改正后的观测数据重新进行分析,得到的M2潮波振幅因子精度均优于0.8‰,去除漂移后的残差时间序列中重力非潮汐变化为(4-10)×10-8ms-2,周日波振幅小于0.1×10-8ms-2,半日波振幅小于0.3×10-8ms-2,较之测定前有明显的改善.因此利用精确的M2潮波振幅因子测定仪器的标定因子,能够保证所有gPhone弹簧重力仪在统一的潮汐基准下观测.