利用GIS技术获取GPS水准的新方法

【作者】 罗孝文；

【导师】 方源敏； 施昆； 吕中树；

【作者基本信息】 昆明理工大学 ， 矿产普查与勘探， 2003， 硕士

【摘要】 现代空间技术的发展和应用彻底改变了空间测量数据采集的方法。GPS(全球定位系统)卫星定位技术利用人造地球卫星，确定地面点的空间位置。目前，地面点的平面位置确定精度已相当高，但高程精度始终未能达到水准测量的要求，因为将GPS大地高转化为水准正常高的拟合推估方法是将局部大地水准面视为数学曲面，常常与实际情况差异较大(特别在西部山区差异更大)。 大地水准面是空间测量数据外业采集所依据的参考基准面。确定全球、一个国家、一个地区的大地水准面的形状始终是测绘科学的一项核心内容，一直未能有快速、简洁、自动的解决方法。需要的天文测量、重力测量、大地测量等数据的密度无法满足其需要。 影响高原山区大地水准面起伏变化的主要原因是地形的剧烈变化，地形量和岩石密度分布的不均匀。而地形资料和岩石密度资料既充足又可靠，用它们来精化高原山区的大地水准面会获得良好的效果。 随着计算机技术的不断发展，计算速度越来越快。也使得地理信息系统(GIS)技术应用领域越来越广泛，MapObjects正是为了满足这种需要而开发出来的。并可以直接嵌人支持ActiveX的应用中，ActiveX对象具有特征和方法，可以通过对它们的编程来控制对象的外观、行为以及相互作用。 本文通过大量参考文献的综述分析，在前辈研究的基础上，主要研究我国西部山区(以云南高原山区为例)确定GPS水准的新方法，目的是为西部山区找到一种快速、实时、自动获取适合于工程测量、工程建设及工程领域科研的精度达到厘米级甚至毫米级的高程异常。在数字地形图和数字岩石密度分布图(有相当数量的数字图已建成)的基础上，利用GIS技术对数字化地形图的等高线和岩石密度数据进行提取，自动获取大量的分块高程数据和岩石密度数据，在此基础上，对格网的顶点采取等高线内插的方法提取出它们的高程，并计算出垂线偏差。更多还原

【Abstract】 With the development and application of the modern spatial technology, the collecting method of spatial data is largely changed. GPS is the technology which use the satellite to measure the 3D coordination of spatial points. Now the 2D precision of spatial points is very great, but because by usual correlation fitting method we can transfer GPS ellipsoidal height into normal height of the local Geoid is considered as mathematical curve plane ,It is not conform the fact of mountainous districts so the precision of elevation is so small that it is not satisfied with the requirement of leveling.Geoid is the reference datum of spatial data collection, so how to ascertain the Geoid, that of all over the world, that of one nation, or that of one zone, is always an nuclear task of surveying science but there is not the quick and automatic solution .The density of the required data of astronomical measurement, gravimeter survey and geodesic survey is not satisfied.The main factors to influence the Geoid s rising and falling of the mountainous districts are the acute change of the landform and the asymmetry of the mass of landform and the density of rocks. But the data of them are ample so it will be effective to dive Geoid by them.With the development of computer technology, the velocity of operation become quicker, at the same time, the application of the GIS technology become wider, Then MapObjects is developed and it may directly inverse the application of bearing ActiveX. In ActiveX objects there are properties and methods then we may program to control the appearance, action and interaction of objects by them.In this paper, basing on many documents and the study of the former investigator, a new method of GPS leveling being directly confirmed will be discussed in order to explore a method to improve precision (which is centimeter or millimeter about the height anomaly) of the engineering surveying, engineering construction and engineering research in the west mountainous districts of China (for example YunNan province). The elevation of the contour line and the density of rock will be get from the digital maps (now there are many digital maps). Basing on it, we can get the elevation of grid by interpolation and calculate the vertical inclination.更多还原