2000国家大地坐标系数据处理的若干技术研究

2000国家大地坐标系(CGCS2000)成果的获取技术涉及国际地球参考框架(ITRF)、参考历元、卫星星历及站点速度场等归算问题.介绍了不同参考框架的转换模型和参数,讨论了获取CGCS2000成果的数据处理方法,利用实测观测数据分析了IERS发布的不同ITRF参考框架和不同国际机构发布的各种不同类型的星历对基线结果的影响,以及直接平差与采用框架转换方法求得CGCS2000坐标成果的差异.结果表明:IGS发布的星历精度要高于其他机构发布的精密星历;不同参考框架的精密星历对基线长度在4000km以内的基线影响小于1.3mm,一般在控制网基线解算时可不考虑卫星星历参考框架的影响;在获取CGCS2000成果时,可不考虑星历的类型、参考框架及历元问题;非ITRF97、2000.0成果可采用框架转换公式及转换参数进行成果归算得到CGCS2000成果.

Study on Some Technologies of Data Processing for China Geodetic Coordinate System 2000

The technology for obtaining China Geodetic Coordinate System 2000(CGCS2000)production is related to the reducing problem of international terrestrial reference framework(ITRF),reference epoch,satellite ephemeris and velocity of station.Conversion model and parameter of different reference frames were introduced,data processing method for obtaining CGCS2000 production was discussed,effects of different ITRFs issued by IERS and satellite ephemerises issued by different international agencies on baseline were analyzed based on the observational data,and the difference of CGCS2000 production obtained by direct adjustment and framework conversion was explained.The results showed that precision of satellite ephemeris issued by IGS was higher than that issued by other agencies;effect of precise ephemeris of different reference frameworks on the baseline was less than 1.3 mm when the length of baseline was less than 4 000 km,and effect of satellite ephemeris reference framework was usually negligible for the control network baseline calculation;for obtaining CGCS2000 production,the problem about the type of satellite ephemeris,reference framework and epoch was negligible;non-ITRF97 and non-epoch 2000.0 production could be converted to CGCS2000 production by reducing calculus production with framework conversion formula and parameter.