航空重力测量的系统误差补偿

Systematic error compensation for airborne gravimetry

基于航空重力测量的基本数学模型,详细分析了航空重力测量的系统误差来源.大致可将系统误差分为三类,即停机坪重力基准值、比力初值的观测误差,格值、交叉耦合系数、摆杆尺度因子的标定误差和水平加速度改正的模型化误差等.然后,对每类系统误差的量级及其补偿方法进行了研究,指出水平加速度改正是引起系统误差的主要因素之一.大同、哈尔滨和渤海湾航空重力测量的实测数据分析均表明,在各项系统误差尤其是水平加速度改正得到有效补偿后,航空重力与地面(或船测)参考值的系统误差将小于1×10-5m·s-2.

Sources of systematic errors in airborne gravity measurements are analyzed in detail using the basic mathematical model. They can be classed into three types. One is the observation error in the apron gravity and the base reading of the airborne gravimeter, the second is the calibration error of cross-coupling correction, beam scale factor and the scale value, and the third is the modeling error for the horizontal acceleration correction. The magnitudes of the various systematic errors are discussed and the related compensation methods are proposed. It is indicated that the modeling error of the horizontal acceleration correction is one of the largest errors. Analysis of real data demonstrates that after compensating the various systematic errors especially the modeling error of the horizontal acceleration correction, the systematic bias between airborne gravity and the ground （or sea） reference value in the Datong and Harbin areas and Bohai Bay are all less thanlX10 -5 m· s-2.