基于广义椭球坐标变换的地球动力学扁率计算  

Earth dynamical flattening calculation based on the generalized ellipsoid coordinate conversion

作　　者：方柳 任红飞[1,2] FANG Liu;REN Hongfei(Xi'an Research Institute of Surveying and Mapping,Xi'an 710054,China;State Key Laboratory of Geo-Information Engineering,Xi'an 710054,China)

机构地区：[1]西安测绘研究所,中国西安710054 [2]地理信息工程国家重点实验室,中国西安710054

出　　处：《测绘科学与工程》2020年第2期68-71,共4页Geomatics Science and Engineering

摘　　要：地球的动力学扁率H是描述地球动力学特性的基本参数,也是研究地球自转、岁差及章动等特性的物理量之一。本文基于广义椭球坐标变换,研究了地球动力学扁率的表达式,以及与几何扁率之间的关系式H=α-1/2α^2,计算得到在近似均质刚体椭球的理想状态下地球的动力学扁率H的值为1/298.7580,与当前观测值的误差约为2%,同时,分析了非理想状态下地球动力学扁率计算的影响因素,如转动惯量4与B不相等、内部密度径向变化等。The Earth dynamical flattening H is a basic parameter to describe the dynamic characteristics of geodynamics,and one of the physical quantities to study the rotation,nutation and precession of the Earth.In this paper,the expression of the Earth dynamical flattening and the relationship with the geometric flattening are derived based on the generalized ellipsoid coordinate transformation.The relationship between H and the geometric flattening a is expressed as H=α-1/2α^2.The calculated value of H under the ideal condition of homogeneous rigid ellipsoid is 1/298.7580,which deviates from the current observation value by 2%.The main influence factors of the Earth dynamical flattening in non-ideal state are discussed,such as inequality between the rotational inertia A and B,and the radial change of internal density.

关 键 词：地球动力学扁率 转动惯量 旋转椭球 几何扁率 坐标变换 

分 类 号：P223[天文地球—大地测量学与测量工程]