区域与全球高程基准差异的确定

发布时间：2018-02-15 11:11

本文关键词： 基准差异重力位差国家高程基准全球高程基准 GPS/水准　出处：《测绘学报》2017年10期 　论文类型：期刊论文

【摘要】：全球高程基准统一是继全球大地测量坐标系及其参考基准统一之后,大地测量学科面临和亟待解决的一个重要问题,也是全球空间信息共享与交换的基础。本文针对区域高程基准与全球高程基准间基准差异确定的理论、方法及实际问题开展研究。利用物理大地测量高程系统的经典理论方法,给出了高程基准差异的定义,并推导了计算基准差异的严密公式,该公式可将高程基准差异确定的现有3种方法统一起来。在此基础上,分析顾及了不同椭球参数对于计算基准差异的影响及量级,同时,高程异常差法还需考虑全球高程基准重力位与模型计算大地水准面位值不一致引起的零阶项改正。利用青岛原点附近152个GPS水准点数据,分别选择GRS80、WGS-84、CGCS2000参考椭球以及EGM2008、EIGEN-6C4、SGG-UGM-1模型,采用位差法和高程异常差法,确定了我国1985高程基准与全球高程基准的差异。其中,EIGEN-6C4模型计算的我国高程基准与WGS-84参考椭球正常重力位U0定义的全球高程基准之间的差异约为-23.1cm。也就是说,我国高程基准低于采用WGS-84参考椭球正常重力位U0定义的全球高程基准,当选取基于平均海面确定的Gauss-Listing大地水准面作为全球高程基准时,我国1985高程基准高于全球基准约21.0cm。从计算结果还可看出,当前重力场模型在青岛周边不同GPS/水准点的精度差别依然较大,这会导致选择不同数据对确定我国85国家高程基准与全球基准之间的差异影响较大,因此,若要实现厘米级精度区域高程基准与全球高程基准的统一,全球重力场模型的精度和可靠性还需要进一步提高。
[Abstract]:After the unification of the global geodetic coordinate system and its reference datum, the global geodetic datum unification is an important problem that the geodetic science faces and needs to be solved urgently. It is also the basis of global spatial information sharing and exchanging. This paper studies the theory, method and practical problem of the difference between regional and global height datum, and makes use of the classical theory method of physical geodetic system. In this paper, the definition of height datum difference is given, and the strict formula for calculating datum difference is deduced. The formula can unify three existing methods to determine the height datum difference. The influence and magnitude of different ellipsoid parameters on the difference of calculation datum are taken into account, and at the same time, The method of height anomaly difference also needs to consider the zero order correction caused by the difference between the global height datum gravity potential and the geoid position calculated by the model. Using 152 GPS leveling data near the origin of Qingdao, the reference ellipsoid of GRS80 WGS-84 CGCS2000 and the EGM2008 EIGEN-6C4SGG-UGM-1 model are selected, respectively, in which the reference ellipsoid of CGCS2000 and the EGM2008 EIGEN-6C4SGG-UGM-1 model are selected. The position difference method and the height anomaly method are used. The difference between China's 1985 and global height datum is determined. The difference between the Chinese elevation datum calculated by EIGEN-6C4 model and the global elevation datum defined by WGS-84 reference ellipsoid U0 is about -23.1cm. The height datum of our country is lower than that of the global height datum defined by WGS-84 reference ellipsoid normal gravity potential U0. When the Gauss-Listing geoid determined based on the mean sea level is chosen as the global elevation datum, The 1985 elevation datum in China is about 21.0 cm above the global standard. It can also be seen from the calculation results that the accuracy of the current gravity field model at different GPS / leveling points around Qingdao is still quite different. This will lead to the selection of different data that will have a greater impact on the determination of the difference between the global and the national height benchmarks of 85 countries in China. Therefore, in order to achieve the unification of the regional elevation datum and the global elevation datum with centimeter precision, The precision and reliability of the global gravity field model need to be further improved.
【作者单位】：武汉大学测绘学院;武汉大学地球空间环境与大地测量教育部重点实验室;
【基金】：国家973计划(2013CB733301) 国家自然科学基金项目(41210006) 国家重点研发计划(2016YFB0501702)~~
【分类号】：P22

【相似文献】