局部重力异常向上延拓的实用算法

针对局部重力异常向上延拓计算复杂、耗时长的问题,该文基于泊松积分离散化的基本原理,提出一种快速的局部格网重力异常向上延拓的实用算法;并结合中国东北和青藏高原地区大地水准面的重力异常格网数据,采用该延拓方法分别计算了空中10、50、100km处的重力异常,将其与等高度的EIGEN-6C4模型结果对比分析。实验结果表明:在顾及边界效应影响的情况下,相对于EIGEN-6C4模型,中国东北和青藏高原地区重力异常向上延拓的最大均方根误差分别优于1.5和3.5mGal;在保证精度可用的前提下,计算效率可以有大幅度提高,证明了该方法解算局部重力异常向上延拓的适用性。

A practical algorithm for upward continuation of local gravity anomalies

Aiming at the problem that upward continuation of local gravity anomalies is complicated and time-consuming,an applied arithmetic for upward continuation of local gravity anomalies was proposed based on the basic principle of Poisson integral discretization.Combining the gravity anomalies grid data of geoid in the northeast and the Tibetan plateau region,the gravity anomalies on the height of 10,50 and 100 km were calculated by using this upward continuation method.The accuracy and applicability of this method was evaluated and compared with the results of EIGEN-6C4 model.The results showed that after taking into account the boundary effect,the maximum RMSE of upward continuation in the northeast and Tibetan plateau region are superior to 1.5 and 3.5 mGal respectively relative to the EIGEN6C4 model;on the premise of ensuring accuracy available,this method could greatly improve the calculation efficiency,which is suitable for upward continuation of local gravity anomalies.