In this study,the terrain correction for lunar free-air gravity anomaly (FAGA) is calculated in spherical coordinates based on the global topography data detected by the laser altimeter on Chang'E-1 (CE-1). The obtained lunar Bouguer gravity anomaly (BGA) reveals density irregularities of the interior mass. BGA is important in characterizing the mascon basins. According to the BGA of the Moon,the South Pole-Aitken (SPA) basin is considered the largest mascon basin on the Moon,and the feature of BGA in the basin implies the impacting direction. Further,the mascon basins seem to be classified into two types,Type Highland and Type Plain. For the mascon basins of Type Highland the dense materials mainly come from the shallow crust,which are associated with the basalt deposits. The other type,Type Plain,includes mascon basins whose major dense materials may be located deep at the litho-sphere,corresponding to the uplifted mantle.
磁异常转换模量(magnitude magnetic transforms,简称MMTs)相比传统的数据处理方法如化极、总梯度模等,其产生的异常更接近实际磁性异常体的水平位置,以便进行磁法解释.本文基于转换模量,提出了磁异常模量的垂向一阶导数的处理方法.进一步分析模量垂向一阶导数的特征可知,对于2D异常体其完全不依赖于异常体的磁化方向;对于3D异常体其弱依赖于异常体的磁化方向.模量垂向一阶导数相比磁异常模量具有更小的中心偏移量和相对峰值;相比其他磁异常转换模量而言,具有计算量小、计算方便等优点.因此,在磁法解释中,磁异常模量垂向一阶导数能更好地确定异常体的水平投影位置以及分布规模.
