区域似大地水准面精化在测量中的应用

发布时间：2018-03-24 06:16

本文选题：似大地水准面　切入点：EGM2008　出处：《西安科技大学》2013年硕士论文

【摘要】：区域似大地水准面精化的主要作用之一，是在一定比例尺地形测图时，用GPS测量代替三角高程测量和水准测量，充分发挥GPS测量的优势，减少外业工作量，降低生产成本。目前，在区域似大地水准面精化中，大多运用大量重力资料、高精度GPS水准数据和数字地形模型，而且内业数据处理和计算过程相当复杂，对于技术、经济实力一般的生产单位而言，几乎是无法做到的，而且很多地区缺乏地面重力数据以及高精度和高分辨率的数字地形模型，因此该方法的应用受到了一定程度的限制。此外，国内研究区域似大地水准面精化还存在拟合点选择是否合理的问题。针对以上问题，本文引入EGM2008地球重力场模型，详尽分析了该模型的精度，特别是该模型在中国大陆地区的精度。然后基于VS2010平台，使用C#语言编写了运用移去恢复法进行区域似大地水准面精化的高程异常计算程序。最后，通过对不同地貌的三种块状测区和两种带状测区的实测数据进行区域似大地水准面精化结果的对比分析，研究了拟合点的选择问题，总结出一种简单易行的小区域似大地水准面精化方法，得到以下结论：（1）对于块状测区，运用EGM2008模型，结合10个左右的GPS水准点，运用移去恢复法，其中拟合方法为二次曲面拟合法，便可计算出该测区高精度的高程异常。如测区地形较为平坦，拟合点个数可减少至8个，如测区地形复杂，可适当增加拟合点个数，具体情况视测区面积与地形复杂程度而定。拟合点的选择十分重要，应尽量选择周围地形无剧烈变化的GPS水准点作为拟合点，，拟合点总体应均匀分布于测区；（2）对于块状测区，基于EGM2008模型，结合GPS水准点，运用移去恢复法进行区域似大地水准面精化是可行的，满足1∶2000及以下比例尺地形图测图中对于图根控制点和碎部点的高程精度要求，可应用于图根控制点与碎部点的正常高测量工作；（3）对于带状测区，运用此方法进行区域似大地水准面精化适用于地形较为平坦的测区，计算所得高程异常的精度，满足1∶2000及以下比例尺地形图测图中对于图根控制点和碎部点的高程精度要求，可应用于图根控制点与碎部点的正常高测量工作，对于地形复杂的带状测区，还需进一步讨论分析。
[Abstract]:One of the main functions of regional quasi-geoid refinement is to use GPS instead of trigonometric leveling and leveling when surveying topography on a certain scale, so as to give full play to the advantages of GPS surveying and reduce the workload of field work. At present, in the process of regional quasi geoid refinement, most of the gravity data, high precision GPS leveling data and digital terrain model are used, and the process of processing and calculating the internal data is very complicated. The application of this method is limited to a certain extent because it is almost impossible for a production unit with average economic strength and lacks ground gravity data and digital terrain models with high accuracy and resolution in many areas. Whether the selection of fitting points is reasonable or not exists in the study area of quasi geoid refinement in China. In view of the above problems, this paper introduces the EGM2008 earth gravity field model, and analyzes the precision of the model in detail, especially the precision of the model in the mainland of China. Then based on the VS2010 platform, Using C # language, the program of height anomaly calculation using the method of removal and recovery for regional quasi geoid refinement is written. Finally, The selection of fitting points is studied by comparing and analyzing the results of regional quasi geoid refinement from the measured data of three blocks and two zonal areas of different landforms. A simple and easy method for quasi geoid refinement in small area is summarized. The following conclusion is drawn: 1) for the block survey area, the EGM2008 model is used, combined with about 10 GPS leveling points, and the method of removing and restoring is used. The fitting method is Quadric surface fitting method, and the height anomaly with high precision in the survey area can be calculated. If the topography of the survey area is relatively flat, the number of fitting points can be reduced to 8, and the number of fitting points can be increased appropriately if the topography of the survey area is complex. The selection of fitting points is very important. The GPS leveling points with no drastic changes in the surrounding terrain should be chosen as fitting points, and the fitting points should be uniformly distributed in the survey area. Based on the EGM2008 model and GPS leveling, it is feasible to use the method of removing and restoring to refine the regional quasi geoid, which can meet the requirements of elevation accuracy of the root control points and fragments in topographic mapping of scale 1: 2000 and below. It can be applied to the normal height survey of map root control points and broken points. For the zonal survey area, this method can be used to refine the regional quasi geoid, which is suitable for the flat topographic survey area, and the accuracy of the height anomaly can be calculated. It can be applied to the normal height survey of root control points and fragments in topographic mapping of scale 1: 2000 and below, and can be applied to the zonal survey areas with complicated topography. Further discussion and analysis are needed.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P223

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