【作者】 张永；

【导师】 张勤；

【作者基本信息】 长安大学 ， 大地测量学与测量工程， 2008， 硕士

【摘要】 长期以来,解决高程测量的主要方法是水准测量,其优点是精度较高,缺点是劳动强度大,成本高、效率低,尤其是对于测区大、线路长、沿线地形复杂多样的交通工程。近来年,GPS以其提供全天候、全球性、高精度、高速度、高效益的实时导航定位服务等优点被广泛应用于各个领域。然而令人遗憾的是GPS在高程定位精度方面还不尽人意,由于似大地水准面是一个不规则的曲面,它无法用一个精准的曲面来模拟,这就使得GPS只能提供给我们高精度的大地高,而不是我们工程中需要的正常高。因此如何有效利用GPS测量的高程信息把大地高转换成正常高,直接为测绘生产服务,实现GPS观测时能同时获得实用的三维坐标,是一个非常实际而又有意义的课题。目前针对面状测区利用GPS转换高程拟合方法把GPS高程信息转换成工程项目需要的正常高这种方法比较常见,技术也较为成熟。而针对长达几十公里甚至几百公里且穿越崇山峻岭的交通工程,如何有效利用大量的GPS高程信息使其成为工程项目需要的正常高,是测量工作者非常关心的问题,也正是本文所研究的问题。本论文介绍了大地高、正常高和正高等高程系统的概念及其相互关系,阐述了GPS测高的相关理论以及GPS水准(GPS高程拟合)的原理,并将GPS高程拟合模型分为函数模型、统计模型、组合模型、重力模型四类,详细阐述了各种模型的拟合方法,并对GPS高程拟合的可行性和各种模型的适用性进行了深入分析,给出了GPS水准拟合精度的评定方法和指标。结合杭州湾跨海大桥工程实例,用Matlab语言编程实现不同的GPS水准拟合方案,对结果进行综合比较、分析和研究,给出了不同拟合模型的精度评价。本文还着重讨论了顾及地球重力场模型的GPS高程拟合方法,从理论上讲,实现GPS大地高向正常高转换的最好方法是综合利用GPS测量数据和地球重力场模型,但对一般工程单位而一言,不具备获得地球重力场模型的能力。文中还结合某高速公路工程数据,利用“移去-恢复”法进行高程转换,采用不同拟合模型与直接拟合结果进行综合比较和分析研究,给出了不同拟合模型的精度评价,并提出了具体的结论和建议。更多还原

【Abstract】 For a long time,the standard measurement to solve the Height Survey is leveling.Though it is precise,it has some shortcomings,such as high labor-intensity,high cost and low efficiency,especially for the traffic engineering which locate in a large measurement area with long range and complicated terrain,In recent years,the GPS,by virtue of such advantages as all-weather service,global observation,high-precision,high-efficiency, low-cost,timely navigation and positioning services,has been widely used in various areas.However,it is regrettable that the positioning accuracy of GPS in elevation is not satisfactory.For example,as the geoid is not a regular surface,the GPS can not find a precise model to simulate it.We could only get the high-precise altitude,which is not essential for our project.It is practical and meaningful subject for us to turn the geodetic height,which we obtain from the GPS,into normal height,make the latter directly serve the mapping and get three-dimensional coordinates through the GPS observation.At present,in the plane measurement area,it is common to use the GPS conversion elevation fitting method to turn GPS height information into a suitable one to the project,for its technology is relatively mature.But when we face the large traffic engineering which goes a few dozen kilometers or even hundreds of kilometers across the mountains,it is a very concerned issue that how tO get the normal height by using quantitative GPS height information.This essay mainly introduces the concepts,mutual relationships of geodetic height、normal height and orthometrie height elevation systems,narrates related theories of the GPS height fitting and the principles of GPS standard(GPS elevation fitting).In addition,GPS elevation model,which has been divided into the function model,the statistical model,the combination model and gravity model,elaborates the fitting methods of various models, deeply analyzes the feasibility of GPS elevation fitting model,applicability of various models presenting the evaluation method and indicators of accuracy of GPS standard fitting. With the Hangzhou Bay Bridge Project and different fitting methods of GPS standard using Matlab programming language,the results have been comprehensively compared,analyzed, researched.The evaluation methods of accuracy of various fitting models have also been presented.Besides,this essay particularly describes the GPS height fitting method,in which the Earth’s gravity have always been taken into consideration.The best way to get GPS land height from the conversion of the normal height is to utilize GPS measurements and Earth’s gravity field model comprehensively in theory.But for the ordinary project department,it does not have access to Earth’s gravity field model.The author illustrates the data of one highway engineering and makes the elevation conversation with the "remove-restore" method in the essay.What’s more,he compares and analyzes those in direct fitting results and different fitting models comprehensively.At last,the accuracy of evaluation of different fitting models have been given and specific conclusions and recommendations have been made.更多还原