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利用分测线零漂改正方法和格值系数变化检测方法,对云南重力测区2014年两期CG-5重力仪观测数据进行了精细处理,获得了该地区重力场变化,并用绝对重力观测结果进行了验证。结果表明:(1)CG-5重力仪零漂率存在明显的随时间变化,C1169和C1170两台重力仪在第一期观测时间内呈近似线性的增大趋势,变化量达20×10~(-8) m·s~(-2)·h~(-1),第二期观测时间内则趋于稳定,经零漂改正后,观测数据联测精度明显提高;(2)C1170重力仪格值系数变化发生了明显变化,变化量约为-0.000 100;(3)经格值系数改正后,获得的重力变化结果与绝对重力观测结果更为一致,重力场变化图像更为清楚地反映了昭通-鲁甸断裂两侧的差异变化和鲁甸6.5级地震的发震背景,验证了大地震一般发生在与主要活动断裂一致的重力场变化正负转换带上这一结论,说明本文所用方法能有效消除观测数据中的系统误差,有利于真实重力场变化信息的获取。
By using the method of zero line correction and the detection of the change of grid coefficient, the CG-5 gravimeter data from 2014 Yunnan Gravimetric Survey Area was finely processed, and the gravitational field changes in this area were obtained. The absolute gravity observations Verified. The results show that: (1) Zero-drift rate of CG-5 gravimeter changes obviously with time. The two gravimeters of C1169 and C1170 increase approximately linearly in the first observation period with a variation of 20 × 10 ~ (-8) m · s ~ (-2) · h ~ (-1), and the second observation period tends to be stable. After the zero drift correction, the accuracy of the joint measurement of observation data increased obviously. (2) The C1170 gravity (3) After the grid coefficient correction, the obtained gravitational change results are more consistent with the absolute gravimetric observations, and the gravitational field change images more clearly It reflects the difference between Zhaotong-Ludian fault and the seismogenic background of the Ludian M6.5 earthquake. It is verified that the large earthquakes generally occur on the positive and negative transition bands of gravity field consistent with the main active faults, The proposed method can effectively eliminate the systematic errors in the observed data and is conducive to obtaining the information of the real gravitational field changes.