用超导重力仪观测数据精密测定地球潮汐常数

基于我国武汉超导重力仪１９８５年１１月２３日至１９９４年１２月３１日（３３２６ｄ共７９８２４ｈ整点读数值）的长周期序列重力潮汐观测数据，利用国际上通用的资料分析方法和计算机软件系统研究了重力场潮汐变化特征，精密测定了地球潮汐常数，几个主要潮波的振幅因子测定精度达０．０４％。对采用不同引潮位展开、是否考虑加权滤波、做气压改正、删除错误数据以及规定数据段均方差上限等方式对提高资料分析精度的影响问题进行了讨论。利用Ｓｃｈｗｉｄｅｒｓｋｉ全球模型对重力潮汐观测分析结果进行了海潮负荷改正，较系统地研究了观测重力残差和台站气压变化之间的相关性，在时间和频率域内测定了相应的大气重力导纳值。与Ｗａｈｒ－Ｄｅｈａｎｔ标准地球潮汐模型相比较，潮汐振幅因子的平均偏差分别是０．４％（Ｏ１波）和０．２％（Ｍ２波）。

ACCURATE DETERMINATION OF THE EARTH TIDAL PARAMETERS USING SUPERCONDUCTING GRAVIMETER OBSERVATIONS

Based on the long series observations from November 23, 1985 to December 31, 1994 (3 326 days, 79 824 hourly readings)observed with superconducting gravimeters at station Wuhan, the characteristics of the tidal gravity varied with time and frequency are systematically investigated using the world wide used high precision data analysis methods and softwares. The tidal parameters are accurately determined, it is found that the average accuracy for several main waves reaches at 0.04%. The efficiency of the various procedures on improving accuracy is also investigated, such as to use tables of different tidal potential development, to consider the weights of the filtered numbers, to correct the air pressure perturbations, to delete the error data, to define the upper limit of the standard deviation for a data section of 48 hours and so on. The oceanic loading corrections on tidal gravity results are made based on Schwiderski global cotidal maps. The relationship between the tidal observations and station air pressure is also systematically studied, the atmospheric gravity admittances in both temporal and frequency domains are determined. Comparing to the Whar-Dehant standard earth tidal models, the average discrepancy of the tidal amplitude factors is given as 0.4% ( O 1 wave) and 0.2% ( M 2 wave).