基于GOCE重力场模型与地形改正的似大地水准面精化

发布时间：2018-04-03 13:07

本文选题：似大地水准面精化　切入点：地球重力场模型　出处：《长安大学》2013年硕士论文

【摘要】：自2009年3月17日GOCE卫星发射以来，卫星重力数据的精度和分辨率得到了极大提高，，GOCE卫星的科学目标之一就是确定全球范围内cm级精度的大地水准面。随着GOCE卫星的成功发射，围绕GOCE数据处理和应用研究将成为今后几年地学研究的热点之一。本文利用GOCE卫星L2产品中的重力场模型数据与SRTM地形数据计算区域似大地水准面高，并对相关理论与方法进行了介绍。论文的主要内容概括如下： (1)介绍了精化大地水准面的基本概念与基本理论，并重点介绍了“移去-恢复”技术。 (2)介绍并比较研究了基于GOCE卫星数据所建立的重力场模型。首先分析了他们的阶方差；其次利用研究区域内GPS/水准数据对所选模型计算得到的大地水准面高进行了比较；最后利用最小二乘原理对模型计算值进行了拟合改正。计算结果表明，利用GOCE卫星数据产品恢复地球重力场模型的三种方法中，直接法精度最高，时域法次之，空域法精度最差；GOCE模型的精度比EGM2008重力场模型的精度降低了约0.2m；GOCE重力场模型在平原的误差约19cm，在山区的误差约42cm。 (3)介绍和分析了常用的超高阶缔合勒让德函数算法，计算结果表明跨阶次递推法的计算速度最快、数值精度最高。 (4)计算分析了地形对大地水准面的间接影响，结果表明，地形起伏越大，对大地水准面的间接影响越大；大地水准面间接影响的计算公式中，主项具有明显的主导作用，次项所占比例不大，在平坦的地区，次项可忽略不计；另外，积分半径对间接影响的计算结果影响不大。 (5)提出了顾及重力场模型与地形改正的“移去-恢复”法，通过实例计算结果表明，这种方法是行之有效的；另外，多项式拟合可以有效的减小重力大地水准面与几何大地水准面的系统误差。
[Abstract]:Since the launch of the GOCE satellite on March 17, 2009, the accuracy and resolution of the satellite gravity data have been greatly improved. One of the scientific objectives of the satellite is to determine the geoid with cm precision in the global scope.With the successful launch of GOCE satellite, the research on GOCE data processing and application will become one of the hotspots of geoscience research in the next few years.In this paper, using the gravity field model data of GOCE satellite L2 and SRTM topographic data to calculate the area quasi geoid height, the related theories and methods are introduced.The main contents of the thesis are summarized as follows:The basic concept and theory of refined geoid are introduced, and the technology of "remove-recover" is introduced emphatically.The gravity field model based on GOCE satellite data is introduced and compared.First, their order variance is analyzed; secondly, the geoid height calculated by the selected model is compared by using the GPS/ leveling data in the study area; finally, the fitting correction of the model calculated value is carried out by using the least square principle.The calculation results show that the direct method has the highest precision and the time domain method is the second among the three methods for restoring the earth gravity field model by using the GOCE satellite data products.Compared with the EGM2008 gravity field model, the precision of the spatial domain method is the worst. The error of the model is about 19cm in the plain and 42 cm in the mountain area.This paper introduces and analyzes the commonly used algorithms of ultra-high order associating Legendre function. The results show that the cross order recursive method is the fastest in calculation and the highest in numerical accuracy.4) the indirect influence of topography on geoid is analyzed. The results show that the larger the topographic fluctuation, the greater the indirect influence on geoid, and the main term plays a dominant role in the calculation formula of indirect geoid influence.The proportion of the second term is not large, but in the flat area, the second term is negligible, and the integral radius has little influence on the calculation results of the indirect effect.(5) A method of "removal and recovery", which takes gravity field model and terrain correction into account, is proposed. The calculation results show that the method is effective.Polynomial fitting can effectively reduce the systematic error between gravity geoid and geometric geoid.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P22

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