利用全张量重力梯度异常探测月球地下隐伏地质结构及其解释

Exploration and Interpretation of Lunar Underground Concealed Structures Using Full Gravity Gradients Anomaly

将有限功率地形法(或称Tesseroid单元体球谐谱域正演法)运用到月球地形的重力梯度计算中,并通过圣杯任务(GRAIL)得到的重力场模型系数和Moontopo720地形模型数据,计算得到在GRAIL卫星高度经过地形校正后的全重力张量异常。综合重力梯度的多分量性质和相关实验结果,首先通过水平梯度异常估算月球主要质量瘤(mascon)的地下空间水平分布范围,然后通过全重力异常梯度带图初步验证潮汐重力引起的月球主要断层结构分布。

We apply the finite power terrain correction method(i.e.,the Tesseroid forward modelling in harmonic spectral domain)to the gravity gradient calculation in terms of lunar topography.Using gravity data from the Gravity Recovery and Interior Laboratory(GRAIL)mission and terrain information recovered from the Moontopo720 model,we calculate the total gravity tensors anomaly after terrain correction at the height of GRAIL satellite.By taking advantage of the multi-component characteristics of gravity gradient and the relevant experimental results,we estimate the spatial horizontal range distributions of underground mascons through the horizontal gradient anomaly.Using the total gravity gradient anomaly maps,we preliminarily verify the distributions of main fault structures caused by tidal gravity.