航空重力空中测线数据内符合精度评价

Evaluation of the internal accord accuracy of airborne gravity survey line data considering position correction

针对航空重力测量受到飞机状态和气流变化等因素影响的特点和常规重复测线对比方法的缺点,该文提出了顾及平面位置纠正和高度归算的重复测线对比分析和交叉点分析方法。选取两两组合模式进行重复测线对比分析,建立多参数精度指标,采用交叉点分析,对毛乌素测区航空重力空中测线数据内符合精度进行评价。结果表明:4条重复测线的绝对平均偏差为0.01~0.95mGal,标准差为0.87~1.44mGal,两两组合对比模式在鉴别问题测线方面更有优势;在231个交叉点处,经过交叉点平差处理,均方根差值从平差前的1.6mGal减小到1.34mGal。

In view of the characteristics of airborne gravity survey,such as the state of the aircraft and the variation of air flow,and the shortcomings of the conventional method for repeated line comparisons,the comparative analysis of repeated survey lines considering horizontal position and height correction and the cross-over analysis are introduced in this work.The internal accord precision of airborne gravity survey line data collected over Mu Us is evaluated.The two-line combination mode is chosen to perform repeated line comparisons,so that a set of multi-parameter precision index is established to evaluate the internal accord precision.Numerical results show that the absolute bias of the four repeated survey lines ranges from 0.01 mGal to 0.95 mGal and the standard deviation ranges from 0.87 mGal to 1.44 mGal.After cross-over adjustment,the RMS of differences at 231 cross-over points reduced from 1.6 mGal（before adjustment）to 1.34 mGal.