利用实测资料确定LCR重力仪的线性格值和周期误差参数

Determination of linear and periodic error parameters for the scale value of LCR gravimeters by observed gravity data

利用3台LCR重力仪在首都圈重力网同步观测的大量实测数据,根据其中2台(G570,G596)的基本参数,解算另一台仪器(G147)的线性格值和周期误差参数。由于该方法联立的误差方程较多(达934个),提高了解算结果的精度。结果表明,LCR147仪器格值线性参数k=0.999 380,比一般的LCR仪器小0.001,且在周期T3=7.88和T5=70.94处存在明显的周期误差,幅值分别为A3=10.2×10-8m/s2和A5=6.3×10-8m/s2;将本文计算的重力仪线性格值与周期误差参数,运用于首都圈重力地震监测的资料处理分析中,不但有效地提高了观测精度,而且对提高重力变化的可信度,削除虚假重力变化信息有重要的意义。

A new measurement to evaluate the parameters of the linear and periodic errors for the scale values of LCR gravimeter is put forward in this paper. Using the gravity data observed in real mobile repeat gravity measurement with 3 LCR gravimeters (G147,G570 and G596), based on the parameters for the two gravimeters of G570 and G596, the parameters for G147 are determined. As much more equations (reaches to 934) are involved in computation, the precision of the results with this method is much higher than that with normai calibration method measured on gravity baseline. The results show that the parameter of linear error for G147 drops to k = 0. 999 380, which is 0.001 smaller than ordinary, and that of significant periodic errors obviously appear at T3=7. 88 and T5=70. 94, with amplitude of A3=10. 2×10-8m/s2 and A5=6. 3×10-8m/s2 respectively. Applying the parameters obtained from this method to process the gravity data observed on China Capital area for earthquake monito-ring, data precision has been effectively raised, reliability on gravity variation has been high-ly improved, and spurious anomaly on gravity has been significantly reduced.