Feedback Scale因子对Burris型相对重力仪观测成果的影响

Effect of Feedback Scale Factor of Burris Gravimeter on Relative Gravity Observation Results

对3台Burris型重力仪系统中的feedback scale因子对相对重力测量成果的影响进行测试分析和研究。结果表明,feedback scale因子值与Burris型重力仪读数线性相关,且线性系数与FBK改正值有关。若feedback scale因子值产生等比例的变化,FBK改正值越大,仪器读数的变化越大。在feedback scale因子值增加时,FBK改正值的正负符号决定仪器读数变化的方向。在重力值差仅有17 mGal的测段上测量时,3台Burris型重力仪基本相同的feedback scale因子变化量,得到的不同重力值差最大可相差0.140 mGal。当同一台仪器在FBK改正值分别为-14.7 mGal和2.2 mGal的2个测点进行测量时,若feedback scale因子值变化2%,测量所得重力值差的变化超过0.300 mGal。

With three Burris relative gravimeters,we study the effect of feedback scale factor in the meter system on relative gravity observation results.The study indicates there are linear relationships between the feedback scale factor and meter readings of Burris.The larger FBK correlation,the larger change of meter readings,and the positive or negative FBK correlation,determine the direction of gravimeter readings variation as feedback scale factor increases.When the three Burris gravimeters are employed to survey a gravity difference that is 17 mGal between two sites,there are variations of gravity difference,although the changes of feedback scale factor are similar and the largest variation is 0.140 mGal.When one Burris gravimeter is used to measure a gravity difference between two sites,where the FBK correlations are-14.7 mGal and 2.2 mGal,the change of measured gravity difference is larger than 0.300 mGal,if the feedback scale factor changes 2%.