重力三层点质量模型的构造与分析

点质量模型理论是研究区域重力场的一个非常重要的方法，本文简要介绍了点质量模型逼近区域重力场的原理，计算分析了构造点质量模型过程中系数矩阵元素的特性。以32~34N和103~105E为计算中心区域，利用EGM2008的720阶次的位系数计算出的重力异常作为观测数据，在36阶次位系数模型的基础上，构造了四层点质量组分频段从低到高来逼近该区域重力场。数值试验的结果表明：三层点质量模型效果较好，点质量模型计算的扰动重力在径向上的截断误差优于2 .

The Construction and Analysis for Three-tier Point Mass Model of Gravity

The theory of the point-mass model is one of the most important methods for the research of the logical gravity field. In this paper, the approximation theory of point-mass model is briefly introduced, and the characteristics of the elements in the coefficient matrix for the model construction are analyzed by numerical calculation. The observations are calculated by using EGM2008 with degree and order 720 in the region of 32~34N and 103~105E. The four-tier point-mass groups based on the geopotential model with degree and order 36 are from low frequency to high frequency to approximate the gravity field. The results of the tests show that the effect of three-tier point-mass model is better than others and the truncation error of gravity disturbance created by using the point-mass model is less than 2 mGal on the radial direction.