以地震监测为目的流动重力重复测量获取的重力年变信号通常在十几到几十微伽量级。但由于重力测点所处的地形高程不同,将空间测点直接插值得到的重力异常空间图像会叠加由于地形起伏引起的异常畸变。本文通过6面体模型定量计算了不同规模和埋深场源的地形效应;对青藏高原东缘地区测网的重力观测数据进行了分析处理,并通过位场曲面延拓校正技术消除了地形影响。结果表明,位场曲面延拓校正技术可以有效地改善重力数据质量,有利于更准确地圈定和认识异常的空间形态特征。

The annual gravity variation in the same measuring position, which is for seismic monitoring by repeated measurement, is about more than a few tens 1 × 10-Sm · s-2 However, since the topography of the measuring position is varying from point to point, the gravity anomaly gained through gridding will be influenced directly. So we calculated the topographic effects with different scales and depth of field sources by the hexahedral model in this paper, and with this as the basis, we analyzed the gravity observation data of the eastern margin of Qinghai-Tibetan plateau, and removed the influence of the terrain by the method of potential field continuation. The results showed that this method was efficient in improving the quality of the gravity data, which was more helpful in cognizing the space characteristics of gravity anomaly and also the gravity field variation by repeated measurements.

国家自然科学基金（41104046）、中国地震局地球物理研究所基本科研业务专项（DQJB11C14）、中国地震局青年震情跟踪课题（2012020204）共同资助