【作者】 杨力；

【导师】 许其凤；

【作者基本信息】 解放军信息工程大学 ， 大地测量学与测量工程， 2001， 博士

【摘要】 随着GPS的发展与应用，对GPS误差源的研究更加精细、更加科学。大气折射是GPS测量的主要误差之一，大气折射误差在很大程度上取决于大气内部结构和测站与卫星的空间几何关系，大气对GPS测量的影响按影响特性分成中性大气影响和电离层影响。国内外通用方法是用大气传播理论来建立大气折射理论和修正模型，本文分别就这两种大气影响作以研究，目的是建立大气修正更为有效的方法。本文的主要内容有： 1.定义中性大气折射，归纳为速度延迟和弯曲延迟两项误差，速度延 迟是主要项，大气弯曲误差的影响程度较小，只有在高度角＜10°或测站 高程较低时才应于考虑，否则会增加10cm左右误差。 2.分析比较全球大气模式与局部大气模式的差别，发现用标准大气模 型修正我国青藏高原大气时，会出现严重修正不足的情况，于是，利用 青藏高原探空气象资料，建立了青藏高原局部大气折射改正模型。 3.系统研究大气折射理论和改正方法，比较各种天顶延迟和投影函数 差异性及灵敏度，认为温度是产生天顶延迟模型差异的主要因素，卫星 高度角较低时投影函数才会有差异。 4.建立大气折射误差对GPS基线影响的估计方法，通过比较基线重复 性，得出随机过程估计方法是计算大气折射最佳方案。 5.提出基于大气预报模式的大气修正理论，尝试了一种修正大气延迟 新的方法，探讨了GPS在气象学中的应用方法，为预报可降水量寻求 新的途径。 6.在电离层折射研究中，分析电离层对GPS的主要影响，依据群延迟、 相延迟和单频、双频影响的主要特性，全面论述了电离层延迟的各种方 法，并重点研究了WAAS的格网改正算法及其所能达到的改正精度。 7.阐述了在差分GPS中，单频接收机的电离层参数修正原理和解算方 法。从大多数电离层修正方法归纳分析，电离层修正的实质是利用了电 离层相关性，电离层的相关程度决定着用户拟合电子含量精度的好坏， 同时，GPS监测电离层是反映电离层相对变化的有效方法。更多还原

【Abstract】 Wth the develoPmnt and aPplication of GPS, the research of errors of GPSbecomes more precise and scientific. AAnosphere refraction is a main error inGPS surveying. The error of atmosphere refraction mainly lies on the innerstfuCtue of inosphere and the SPatial relation of Station and satellite. Based onthe characteristic of atmosphere influence, the atmosphere affection to GPSsurveying is divided into the neuter atmosphere affection and the ionosPhereaffection. It is a cornrnon method for domestic and overseas researchers to use thetheory of driosphere propagation to establish the theory of aAnosphere refractionand the correcting model. In order to estabIish a more effective method fOrcorrecting, tWo kinds of atmoSPhere affection in GPS surveying are studied inthis paPeLThe main achievements of this paPer are as follows’l. The basic concept of troPospheric refraction is defined. It is reduced tospeed delny and inflecting delay. Thereinto, the speed delay is themajor error other than the inflecting delay. Only if When the satelliteelevation angle is less than l0 degree or the altitude of station is verylow the infiecting delay is taken into account. Othebose, the error wllincrease about l0cm.2. By analyzing and comparing differences betWeen the globalatriosPhere mode1 and the 1ocal atmosphere model, it is found that thecorrect is very deficient when the aAnosphere of the Qing-ZangTableland is corrected with the standard atmosphere model. TherefOre,by using meteorologic data of the Qing~Zang TabIeland, the locaIaAnosPhere refraction correction model of the Qing-Zang Tableland isPut rorwaru.3. Theories of atInosphere refraction and correcting methods areresearched systemically And differences and sensitivities of aIl kindsof zenith delays and projection functions are compared. Thus,temperature is regarded as the main factor to bring differences betweenzenith deIay models and there are some diff’erences between Proectionfunctions only when the satellite elevation angle is small.4. An estimation teclmique used fOr estimating the atmosphere affectionin GPS surveying is set uP. By comparing baseline repetition, it isllconcluded that the random estimation process is the best solution for calculating atmosphere refraction.5.Based on atmosphere forecasting mode, the theory of atmosphere correction is brought forward and a new method for correcting the atmosphere delay is attempted. And methods for application of GPS in meteology are studied, which provide new approaches for forecasting precinpitable water.6.The main affection of ionosphere to GPS is analyzed. Based on the main characteristic of group delay and phase delay or the primary characteristic of single frequency and double frequency, all kinds of techniques are discussed. Furthermore, the arithmetic of grid correction and its corrective precision in WAAS are studied.7.In DGPS, principles and methods for correcting ionosphere parameters of single frequency receiver are introduced. Analyzing from most ionosphere correction methods, we know that the essential characteristic of ionosphere correction is that it take advantage of the correlation of ionosphere. The degree of correlation determines user抯 total electron content. Besides, it is an effective way to use GPS to reflect relative changes of ionosphere.更多还原