【作者】 杨洪国；

【导师】 范东明；

【作者基本信息】 西南交通大学 ， 大地测量学与测量工程， 2011， 硕士

【摘要】 GPS技术已经广泛应用于大地测量、工程测量、摄影测量与遥感、地壳运动监测、工程变形监测、地球动力学等多学科领域,它可同时精确测定三维大地坐标,并且通过精密似大地水准面,可将GPS点的大地高转换为正常高,从而代替普通水准测量。地球重力场模型和大地水准面的确定是重力卫星研究的主要内容,因此重力卫星研究的成就是继GPS技术之后的又一次革命性突破,它不仅带动了现代大地测量学的变革,还推动了其他相关学科的发展。在精密工程测量中,将高分辨率的地球重力场模型与高精度的GPS相结合,可以提高GPS高程转换精度。不同地球重力场模型的优选及不同拟合方法的合理选择是GPS高程转换所需考虑的关键问题。随着以卫星重力梯度为主要观测值的GOCE重力卫星的发射成功及其相关重力场模型的推出,使得地球重力场模型的精度及分辨率有了较大提高,有必要将其应用于GPS高程转换的研究；现在精密工程测量中GPS与全站仪的共用是普遍存在的事实,这必然存在法线系统与垂线系统的转换问题,以往由于重力场模型精度较低,未能充分顾及到这种差别,而利用现有最新的地球重力场模型,能较精确地计算垂线偏差并将其应用于精密工程测量。针对以上问题,本文提出了用目前具有较高精度的EGM2008和SGG地球重力场模型来代替以往较低精度地球重力场模型的策略,计算分析了这两种模型解算全球高程异常的精度,并将这两种模型应用于“移去-拟合-恢复”法的GPS高程转换中,可较好地移去高程异常的系统偏差,在此基础上分析了平面法、二次曲面法、正双曲面法、倒双曲面法及样条函数法用于高程异常拟合的精度,并通过某实际隧道工程算例验证了各种方法的精度。针对精密工程测量的特点,本文提出了顾及垂线偏差的GPS与全站仪的精密数据处理方法,通过“三差改正”将全站仪观测值转化为法线系统下的观测值,与GPS数据统一处理,利用某隧道算例验证了地球重力场模型对平面控制网数据处理的影响不容忽视。更多还原

【Abstract】 In current days, GPS technology has been widely used in geodesy, engineering surveying, photogrammetry and remote sensing, crustal movement monitoring, deformation monitoring, geodynamics, and other research areas, it can simultaneous determine precise three-dimensional geodetic coordinate. Once the local geoid is determined, the ellipsoidal height of GPS point can be easily transformed to quasi-geoid height through precise quasi-geoid to replace the geometric leveling. The Earth gravity model and the determination of geoid is the main research area of gravity satellite, and the achievement of the gravity satellite research is another revolutionary breakthrough after GPS technology, which not only led to change in modern geodesy but also promote the development of other related disciplines. In precise engineering surveying, by combining high resolution gravity model with high precise GPS surveying, it is possible to improve the accuracy of GPS height transformation.The key problem of transferring GPS leveling is to get an optimal combination of different gravity models and a reasonable selection of different fitting methods. Along with the successful launching of GOCE gravity satellite which takes gravity gradient as main observations and its related production of gravity model which greatly improves the accuracy and resolution of the Earth gravity model, and it is necessary to apply it to GPS leveling transformation. It is common to use both of GPS and total station in current precise engineering survey, which leads to the transformation problem between normal and vertical system. Because of the low precision of gravity model in the past, the effect of the problem is ignored. But now, with the latest available gravity field model, it is possible to calculate the vertical deflection and apply it to precise engineering survey.Considering the problems mentioned above, the thesis proposes the method of using the latest higher precise EGM2008 and SGG gravity model to replace the gravity model in the past and analyzes the precision of height anomaly calculated respectively by two models. The thesis also applies the two models to the method of recovery - fitting- restore of GPS leveling transformation which can effectively remove the system error caused by height anomaly. Based on this the thesis analyzes the fitting accuracy of plane method. quadratic surface method, two-surface method, inverted double surface method and spline function method that is used to height anomaly fitting and validates the precision respectively by actual data of a actual tunnel project. According to the characteristic of precise engineering survey, the thesis proposes the precise GPS and total station data processing method taking the vertical deflection into account. The method first transform the total station observation data from normal to vertical system and then process data together with GPS data. According the actual tunnel project example, the result shows that the effect of the earth gravity model on plane control network can not be ignored.更多还原