一种改进的航空重力测量数据处理方法

An Modified Method for Airborne Gravimetry Data Processing

目前的航空标量重力测量系统主要是在当地坐标系下求解重力垂向分量,该方法涉及厄特弗斯改正,却没有考虑垂线偏差的影响。改进方法在准惯性坐标系下求解重力观测量,给出了一个计算重力值的改进公式,避免了经典方法中的近似处理,从理论上完善了航空重力测量数据处理方法。实例验证了改进方法的正确性,并显示经典方法中的近似处理在实验区域内产生了亚mGal级的误差,这个误差在利用1/60s以下的截断频率进行低通滤波后基本可以忽略。除了理论上对经典方法的改进,改进方法还提供了确定扰动重力水平分量的公式,经过细致的数据处理后其精度可达mGal级。

At present,Vertical components gravity is measured and solved in a local frame with the Etvs correction in airborne scalar gravimetry systems.The classic method ignores the vertical deflection effect.In this study,an improved formula is presented and the gravity measurement problem is solved in a quasi-inertial frame.The modified method improves the classical formulas for scalar systems theoretically,avoiding computing Etvs and other approximations.The method was validated using a numerical test.The results show that the unnecessary approximations found in the traditional method will cause sub-mGal level errors.However,these errors can become almost negligible after applying a low-pass fillter with cut-off frequency at less than 1/60 s.In addition to this theoretical advantage,the modified method can acquire mGal-level horizontal gravity estimates through a precise data processing.