应用格林积分直接以地面边值确定外部扰动重力场

摘要

By using the ground as the boundary,Molodensky problem usual ly gets the solution in form of series.Higher order terms reflect the correction between a smooth surface and the ground boundary. Appl ication difficulties arise from not only computational complexity and stabi l ity maintenance,but also data-intensiveness.Therefore,in this paper,starting from the appl ication of external gravity disturbance, Green formula is used on digital terrain surface.In the case of ignoring the influence of horizontal component of the integral,the expression formula of external disturbance potential determined by boundary value consisted of ground gravity anomal ies and height anomaly difference are obtained,whose kernel function is reciprocal of distance and Poisson core respectively.With this method,there is no need of continuation of ground data.And kernel function is concise,and suitable for the stochastic computation of external disturbing gravity field.%以地面为边界的 Mo l odensky 问题通常得到的是级数形式的解，高阶项体现了地面边值到某一光滑面上的改正，在应用中不仅遇到计算的复杂性、稳定性问题，也存在对数据密集要求的困难。本文从推求外部扰动重力场的应用出发，将格林公式用于数字地形面，在忽略水平分量的积分影响的情况下，得到以地面重力异常和高程异常差为边值确定外部扰动位的表达式，其核函数分别为距离倒数和Po i sson 核。该方法不需要对地面数据进行延拓处理，且核函数形式简洁，适于外部扰动重力场的随机计算。