IERS1996规范中地球引力势模型和测量模型的改进

简要而系统地介绍ＩＥＲＳ１９９６规范采用的地球引力势模型和各种测量模型，着重叙述了其与ＩＥＲＳ１９９２标准相比所作的改进。规范用ＪＧＭ－３地球引力势模型取代ＧＥＭ－Ｔ３模型，在计算地球潮汐形变产生的附加势时展开到３阶，并考虑了地幔的滞弹效应。在测站位移的计算中，规范引入了３倍洛夫数，计及地幔的滞弹性，引入了计算冰后期回弹的ＩＣＥ－４Ｇ模型，列出了改正ＶＬＢＩ观测中天线形变改正的公式。关于地球自转和

Improvements of the Geopotential and Measurement Models in the IERS 1996 Conventions

The Geopotential and Measurement Models adopted by IERS 1996 Conventions are briefly and systematically presented, and the major improvements relative to IERS 1992 Standards are described. In the Conventions the geopotential model JGM-3 is applied instead of GEM-T3.The geopotential is developed up to degree 3 and the visco-elastic effect of the earth mantle is taken account in calculating tidal deformation. In the calculation of site displacement, 3-degree Love numbers are introduced, the viscosity of the earth mantle is considered, the ICE-4G model of postglacial rebound is applied, and the formulae of removing antenna deformation in VLBI observations are given. For the tidal variations in the earth's rotation and polar motion,diurnal and subdiurnal zonal tide terms are considered in the Conventions. For the refraction and delay in the troposphere, three new mapping functions are given by the Conventions. For the solar radiation pressure reflectance, the T3 model is introduced. All these models are used to guarantee a precision of 1 mm. But some of them need to be improved further.