LaCoste & Romberg航空重力仪的交叉耦合改正
Cross-Coupling Correction for LaCoste&Romberg Airborne Gravimeter
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摘要: 基于最小二乘原理,分别利用地面重力测量数据、交叉点重力异常不符值对CC(cross-coupling)监视项系数进行了重新标定,同时给出了CC监视项系数和摆杆尺度因子的联合标定方法。试验结果表明,采用新系数显著地降低了空中重力异常估值的系统误差,对于大同航空重力测量,系统误差从4.8 mGal减小至1.8 mGal。Abstract: The cross-coupling corrections for the LaCoste&Romberg airborne gravimeter are computed as a linear combination of 5 so-called cross-coupling monitors,the weight factors(coefficients) determined from marine gravity data by factory are obviously not be optimal for airborne application.These coefficients are recalibrated to minimize the difference between airborne data and upward continued surface data(external calibration) and to minimize the errors at line crossings(internal calibration) respectively.An integrating method to simultaneously recalibrate the above-mentioned coefficients and the beam scale factor is also presented.Numerical results show that the systemic errors in the airborne gravity anomalies can be greatly reduced using any of the recalibrated coefficients.For example,the systemic error is reduced from 4.8 mGal to 1.8 mGal in Datong test.