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从高程系统定义出发,探讨高程基准面的重力等位性质,测试分析不同类型高程系统地面点高程之间的差异,考察GNSS代替水准与实际水准测量成果的一致性,进而提出新的GNSS代替水准算法。主要结论包括:(1)当精度要求达到厘米级水平时,正常高的基准面也应是大地水准面。中国国家1985高程基准采用正常高系统,其高程基准面是过青岛零点的大地水准面。(2)近地空间中等解析正高面与大地水准面平行,GNSS代替水准能直接测定地面点的解析正高,但正常高系统更有利于描述地势和地形起伏。(3)本文给出的GNSS代替水准测定近地点正常高算法,大地高误差对正常高结果的影响比大地水准面误差大,前者影响约为后者的1.5倍。 相似文献
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一、概述 1．问题的提出 国家平面控制网测量成果都是归算到大地水准面再投影到高斯平面上。在实际工程施工中，一般只将导线测量的成果归算到测区平均高程面上。但是，当测区内的导线处于高程较高且远离该带中央子午线时，必须进行大地水准面和高斯平面改正。本结合杭(州)—金(华)—衢(州)高速公路四合同路段线路位于投影带边缘的特点，以新领隧道段为例，详细介绍了该段控制测量成果的处理方法与步骤。 相似文献
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在一般的地形测量中,GPS测量已成为获得点的平面坐标的最主要的方法。但是,GPS 3维坐标中测得的大地高未能在生产实际中发挥应有的作用。因此,需将GPS大地高转换成正常高。本文在实地的地形测量中,根据已有点的高程数据和联测的GPS高程数据,采用等值线图示法和平面拟合法对测区内进行GPS高程拟合,并对两种方法的拟合精度进行比较。最终认为在平坦地区等值线图示法要比平面拟合法更好些。 相似文献
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郭范春 《测绘与空间地理信息》2013,(5):203-204,207
在ADS 80数据处理时,平面涉及到3种坐标系,高程也要把大地高转换为正常高。本文结合辽宁省农村集体土地确权登记发证工作阐述了1980西安坐标系、CGCS 2000国家大地坐标系、WGS-84坐标系之间的转换方法及高程转换问题。 相似文献
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利用GPS技术测量点的平面位置可获得较高精度,但不能直接得到地面点的正常高,只能得到大地高。作者探讨了GPS高程拟合的精度与起算点的分布、整体拟合和分区拟合方法的选择、GPS高程拟合精度的分析等方法并提出了自己的见解,且通过铁岭县C级GPS网的高程拟合实例,介绍了该方法的具体应用。 相似文献
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西南边境地区地形复杂、山高坡陡、交通不便,采用常规的水准测量方法测量极为困难。本文引入最新的EGM2008地球重力场模型用于西南边境地区的GPS高程拟合,并探讨与分析了基于EGM2008地球重力场模型的高程拟合精度。本文以云南省"兴地睦边"农田整治重大项目中的某高山地测区为例,结合常规高程拟合数学模型与EGM2008地球重力场模型,建立区域似大地水准面精化模型进行GPS高程拟合,其结果与常规高程拟合数学模型的结果进行对比分析。 相似文献
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GPS测量的大地高精度达到了(3～4)×10-6,本文结合城镇控制测量对GPS高程拟合情况进行了分析。研究结果表明,通过施测少量均匀分布的GPS点的水准高程,采用BP神经网络方法拟合GPS点正常高可以部分替代水准高程或三角高程。 相似文献
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介绍了各种不同GPS测量的特点和数据处理方法，结合珠峰峰项GPS观测自然环境恶劣的特点，分析了各种计算方案，确定了一种合理的解算珠峰高程的GPS数据处理方案；取得了较为满意的计算结果。 相似文献
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DANG Yamin CHENG Chuanlu CHEN Junyong ZHANG Peng 《地球空间信息科学学报》2007,10(2):79-84
Determining the geodetic height of Mount Qomolangma was one of the very important missions in the 2005 Qomolangma height survey. There were three GPS networks in the survey: regional GPS crustal deformation network, geodetic GPS control network, and GPS measurement on the mountain summit. Data collection and processing were introduced. The final data processing strategy and reasonable geodetic height were fairly determined based on careful data analysis. 相似文献
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GPS与地面测量数据的三维联合平差 总被引：15，自引：4，他引：15
本文论述了ＧＰＳ网在国家或局部坐标系中的三维联合平差与约束平差的函数框民随机模型，讨论了ＧＰＳ网三维平差中的数据处理过程和某些处理技术，这些都是在ＧＰＳ网平差中实用的和必不可少的。最后还介绍了根据这一数学模型所研制的平差软件的某些功能和特点。 相似文献
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Xiuxiao Yuan Jianhong Fu Hongxing Sun Charles Toth 《ISPRS Journal of Photogrammetry and Remote Sensing》2009,64(6):541-550
In traditional GPS-supported aerotriangulation, differential GPS (DGPS) positioning technology is used to determine the 3-dimensional coordinates of the perspective centers at exposure time with an accuracy of centimeter to decimeter level. This method can significantly reduce the number of ground control points (GCPs). However, the establishment of GPS reference stations for DGPS positioning is not only labor-intensive and costly, but also increases the implementation difficulty of aerial photography. This paper proposes aerial triangulation supported with GPS precise point positioning (PPP) as a way to avoid the use of the GPS reference stations and simplify the work of aerial photography.Firstly, we present the algorithm for GPS PPP in aerial triangulation applications. Secondly, the error law of the coordinate of perspective centers determined using GPS PPP is analyzed. Thirdly, based on GPS PPP and aerial triangulation software self-developed by the authors, four sets of actual aerial images taken from surveying and mapping projects, different in both terrain and photographic scale, are given as experimental models. The four sets of actual data were taken over a flat region at a scale of 1:2500, a mountainous region at a scale of 1:3000, a high mountainous region at a scale of 1:32000 and an upland region at a scale of 1:60000 respectively. In these experiments, the GPS PPP results were compared with results obtained through DGPS positioning and traditional bundle block adjustment. In this way, the empirical positioning accuracy of GPS PPP in aerial triangulation can be estimated. Finally, the results of bundle block adjustment with airborne GPS controls from GPS PPP are analyzed in detail.The empirical results show that GPS PPP applied in aerial triangulation has a systematic error of half-meter level and a stochastic error within a few decimeters. However, if a suitable adjustment solution is adopted, the systematic error can be eliminated in GPS-supported bundle block adjustment. When four full GCPs are emplaced in the corners of the adjustment block, then the systematic error is compensated using a set of independent unknown parameters for each strip, the final result of the bundle block adjustment with airborne GPS controls from PPP is the same as that of bundle block adjustment with airborne GPS controls from DGPS. Although the accuracy of the former is a little lower than that of traditional bundle block adjustment with dense GCPs, it can still satisfy the accuracy requirement of photogrammetric point determination for topographic mapping at many scales. 相似文献
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C. S. Fraser 《The Photogrammetric Record》1995,15(86):263-275
This paper addresses aspects of relative observational weighting for GPS camera station positions, ground control and image co-ordinate data in GPS aerial triangulation. Weighting implications for different control point and drift parameter scenarios are discussed, a two stage adjustment/transformation procedure is proposed and the implications of observational weighting on triangulation precision are reviewed. Bundle block adjustment results from a 626 photograph, 1650 point GPS aerial triangulation project are presented to illustrate the outcomes of different weighting and ground control strategies. 相似文献
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珠峰高程复测有关问题的探讨 总被引：3，自引：0，他引：3
较系统地回顾了国内外珠峰高程测量的基本概况,介绍了利用传统大地测量方法和利用GPS技术测定珠峰海拔高程的基本方法,并据此分析了珠峰海拔高程测定的几种关键因素。结合介绍珠峰高程测量的新技术及其对珠峰高程测量的影响,对我国即将开展的珠峰高程复测可能涉及的一些问题做了初步探讨。 相似文献
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长江口12.5 m深水航道投入运行后,每年直接经济效益超百亿元,为保障航道经济效益及水深的持续稳定,掌握长江口水位站高程数据十分重要,但这一特殊的海域地理位置使得传统高程测量方式凸显不足。本文通过将GPS测高技术应用到海陆交叉特殊地域,来获取水位站正常高。结合本区域已有似大地水准面的精化成果,主要采用布设B级GPS网,利用GAMIT基线解算软件、GPS-NET网平差软件保障数据处理质量,并用MEstimators对平差残差进行粗差探测等综合方式。研究结果表明,在海陆交叉地域,此种方式能够达到三四等级水准测量的精度要求。 相似文献