融合卫星重力场信息的区域（似）大地水准面精化方法研究

发布时间：2018-06-23 01:27

本文选题：卫星重力数据 + 多源重力数据　；参考：《东北大学》2013年硕士论文

【摘要】：区域(似)大地水准面的确定涉及多类观测数据的多项复杂计算,目前建立区域(似)大地水准面模型最常用方法是几何与重力联合法,即结合重力数据、DTM/DEM地形数据及地球重力场模型实现区域(似)大地水准面精化。但地面实测重力数据存在着数据分布不均匀及获取困难等问题,且随着卫星重力数据在精度和分辨率两方面的迅速提高,重力测量数据日益丰富和多源化。本文的研究目标是如何将这些具有不同频谱、高度、误差特性的重力信息有效融合起来,在融合过程中消除数据间的矛盾和差异,从而获得可靠、统一的重力基础数据,将其解算结果应用于区域(似)大地水准面的构建。论文的主要研究内容有：(1)对重力场球谐函数进行详细的剖析,推导完全规格化缔合勒让德函数,利用EGM2008地球重力场模型作为参考重力场,引入迭代法完成卫星重力数据的自适应融合处理,使其相互补充。并选取广西北部湾的两个区域进行试验对比分析,结果表明,新、旧模型之间的较大偏差存在于180阶以内,融合后的局部重力场得到了明显的精化。(2)在实现卫星重力数据融合的基础上,研究重力数据、DEM地形数据与确定区域重力大地水准之间的精度关系,通过计算地形间接影响值、直接影响值、地形改正值及残差大地水准面差距,分析确定重力大地水准面的各分量及影响因素,推导具体地形条件下的各类观测数据及其匹配组合与模型成果精度的解析关系,构造由观测数据具体技术指标估计模型成果精度的严格模拟算法。结果表明,计算得到的大地水准面精度较理想,在大地水准面精化的计算中,可与地面实测重力数据相结合或在地面实测重力数据空白区作为一种替代的重力数据。(3)设计开发了(似)大地水准面精化软件,并通过工程实例进行验证,分析观测数据与模型精度之间因果关系的细节特征,实现由观测数据具体技术指标到模型成果精度的精确估计及模拟优化设计。研究结果证明,拟合精度最好的是基于EGM2008模型确定的似大地水准面,同时也验证了利用(似)大地水准精化软件,结合经自适应融合处理的局部重力数据和DEM地形数据,基本能够满足厘米级(似)大地水准面精化要求。
[Abstract]:The determination of regional (quasi-) geoid involves many complicated calculations of many kinds of observational data. At present, the most commonly used method to establish regional (quasi-) geoid model is the combined method of geometry and gravity. Combining the gravity data with DTM / Dem topographic data and the gravity field model, the regional (quasi-) geoid can be refined. However, there are some problems such as uneven distribution and difficulty in obtaining ground gravity data. With the rapid improvement of satellite gravity data in terms of accuracy and resolution, gravity data are increasingly rich and multi-source. The research goal of this paper is how to effectively fuse the gravity information with different spectrum, height and error characteristics, and eliminate the contradiction and difference between the data in the process of fusion, so as to obtain reliable and unified gravity basic data. The results are applied to the construction of regional (similar) geoid. The main contents of this paper are as follows: (1) the spherical harmonic function of gravity field is analyzed in detail, the fully normalized associated Legendre function is derived, and the EGM2008 earth gravity field model is used as the reference gravity field. The iterative method is introduced to realize the adaptive fusion of satellite gravity data, which is complementary to each other. Two regions in the Beibu Gulf of Guangxi are selected for comparative analysis. The results show that the deviation between the new and the old models is within 180 orders. The local gravity field after fusion is obviously refined. (2) based on the fusion of satellite gravity data, the accuracy relationship between Dem topographic data and the determination of regional gravity geoid is studied. Direct influence value, topographic correction positive value and difference of residual geoid are analyzed and each component and influencing factors of gravity geoid are analyzed and determined. The analytical relationship between various observation data and their matching combinations under specific topographic conditions and the precision of the model results are derived, and a strict simulation algorithm is constructed to estimate the accuracy of the model results from the specific technical indicators of the observation data. The results show that the precision of geoid calculated is ideal, and in the calculation of geoid refinement, It can be combined with ground gravity data or can be used as a substitute for gravity data in blank area of ground gravity data. (3) the software of geoid refinement is designed and developed, and verified by an engineering example. The detailed characteristics of causality relationship between observation data and model accuracy are analyzed, and the precise estimation and simulation optimization design from the specific technical indicators of observation data to the precision of model results are realized. The results show that the best fitting accuracy is the quasi geoid based on EGM2008 model. At the same time, it is verified that the local gravity data and Dem topographic data are combined with the software of geoid refinement. Basically can meet the centimeter level (similar) geoid refinement requirements.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P223.0

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