利用电离层延迟改正模型提高GPS高程测量值的精度的研究
发布时间：2018-09-05 09:13
【摘要】：GPS由于其高效方便,得到了迅猛发展,成为了现在地形测量、变形监测、低等级高程控制测量的首选。近年来在GPS理论和技术高速发展的带动下,GPS在平面测量精度和高程测量精度方面都得到了很大的提高。硬件方面,扼流圈天线使得GPS的多路径效应得到了有效的消除；理论方面,各种对流层、电离层延迟改正模型的提出及其应用,以及许多研究表明有效的GPS消除误差理论的应用,使得GPS的诸多与卫星及接收机之间的误差得到了很好的改正,所以GPS在平面位置和高程的测量精度也进一步提高,在平面测量中的精度达到甚至小于±1mm+lppm。由于GPS测量的大地高应用于实际时需要经过高程转换为正常高,中间转换过程中需要解算高程异常,一系列的计算使得GPS在高程控制测量方面误差偏大,影响了GPS高程控制测量在许多方面的应用。本文在GPS双频观测的基础上,通过解算GPS原始的观测数据,建立一种区域的电离层延迟改正模型,取代现在最常用的克罗布歇模型来消除电离层对GPS测量的影响,更好的消除电离层延迟的影响,以提高GPS的解算数据的精度。 区域模型建立采用多项式电离层延迟改正模型,将整个电离层中电子浓缩在一个单层,单层高度取350km,将单层上的垂直方向上的总电子含量(VTEC)的值看作是纬度和太阳时角的函数,计算穿刺点的位置。根据在某段时间内接收机接收到的卫星的观测数据,并将这些观测数据通过TEQC数据处理软件进行处理,限制卫星的高度角,分离出需要的数据,解算多项式中的系数及诸多难以在公式间求差消除的系统误差总量,利用最小二乘法拟合出这些未知项的最优解,进而建立区域性电离层延迟改正模型。利用这种模型解算电离层延迟量且与实际的延迟量进行比较,验证模型的效果。这种在双频测值的基础上,精确求定穿刺点上空的电子含量,反求出多项式模型中的系数建立区域电离层延迟改正模型,更具有针对性的解决当地的电离层延迟量。 通过实际应用的例子来比较本文中建立的多项式模型对实际电离层延迟的改正效果,验证本模型的优势,说明多项式模型更具有针对性,特定性。但是由于建立模型的先天条件也限制了本模型在预报电离层延迟方面的不足。综合模型的优劣性的比较,应用这种GPS双频观测值建立起来的区域性多项式电离层延迟改正模型可以很好的提高GPS的测量精度,也使得GPS在高程控制测量方面得到更广泛的应用。
[Abstract]:Because of its high efficiency and convenience, GPS has been developed rapidly and has become the first choice of topographic survey, deformation monitoring and low grade height control survey. In recent years, with the rapid development of GPS theory and technology, the accuracy of plane measurement and elevation measurement has been greatly improved. In the aspect of hardware, the choke coil antenna can effectively eliminate the multipath effect of GPS. In theory, various models of tropospheric and ionospheric delay correction are proposed and applied. And many studies show that the effective application of GPS erasing error theory makes many errors between GPS and satellite and receiver get very good correction, so the measurement accuracy of GPS in plane position and elevation is further improved. The accuracy in plane measurement is even less than 卤1mm lppm.. Because the geodetic height measured by GPS needs to be converted from height to normal height when it is applied in practice, the height anomaly needs to be solved in the process of intermediate conversion. A series of calculations make the error of GPS in height control measurement too large. It affects the application of GPS height control measurement in many aspects. On the basis of GPS dual-frequency observation, a correction model of ionospheric delay in the region is established by solving the original observation data of GPS, which replaces the most commonly used Krobuch model to eliminate the influence of ionosphere on GPS measurement. The effect of ionospheric delay is better eliminated to improve the accuracy of GPS data. A polynomial ionospheric delay correction model is used to establish the regional model. The electrons in the whole ionosphere are concentrated in a single layer and the height of the single layer is 350 km. The total electron content (VTEC) in the vertical direction of the monolayer is regarded as a function of latitude and solar time angle. Calculate the location of the puncture point. Based on the satellite observation data received by the receiver over a certain period of time and processed by the TEQC data processing software, the height angle of the satellite is limited and the required data are separated. In order to calculate the coefficients in the polynomial and the total systematic errors which are difficult to eliminate the difference between the formulas, the least square method is used to fit the optimal solutions of these unknown terms, and then the regional ionospheric delay correction model is established. The model is used to calculate the ionospheric delay and compare with the actual delay to verify the effectiveness of the model. Based on the dual-frequency measurements, the electron content above the puncture point is accurately determined, and the coefficients in the polynomial model are used to establish the regional ionospheric delay correction model, which can solve the local ionospheric delay. The correction effect of the polynomial model to the real ionospheric delay is compared with the practical application examples. The advantages of the model are verified. It is shown that the polynomial model is more specific and specific. However, the inborn condition of establishing the model also limits the deficiency of this model in predicting the ionospheric delay. Comparing the advantages and disadvantages of the model, the regional polynomial ionospheric delay correction model based on the GPS dual-frequency observations can improve the measurement accuracy of GPS. It also makes GPS more widely used in height control measurement.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P228.4
本文编号：2223837
[Abstract]:Because of its high efficiency and convenience, GPS has been developed rapidly and has become the first choice of topographic survey, deformation monitoring and low grade height control survey. In recent years, with the rapid development of GPS theory and technology, the accuracy of plane measurement and elevation measurement has been greatly improved. In the aspect of hardware, the choke coil antenna can effectively eliminate the multipath effect of GPS. In theory, various models of tropospheric and ionospheric delay correction are proposed and applied. And many studies show that the effective application of GPS erasing error theory makes many errors between GPS and satellite and receiver get very good correction, so the measurement accuracy of GPS in plane position and elevation is further improved. The accuracy in plane measurement is even less than 卤1mm lppm.. Because the geodetic height measured by GPS needs to be converted from height to normal height when it is applied in practice, the height anomaly needs to be solved in the process of intermediate conversion. A series of calculations make the error of GPS in height control measurement too large. It affects the application of GPS height control measurement in many aspects. On the basis of GPS dual-frequency observation, a correction model of ionospheric delay in the region is established by solving the original observation data of GPS, which replaces the most commonly used Krobuch model to eliminate the influence of ionosphere on GPS measurement. The effect of ionospheric delay is better eliminated to improve the accuracy of GPS data. A polynomial ionospheric delay correction model is used to establish the regional model. The electrons in the whole ionosphere are concentrated in a single layer and the height of the single layer is 350 km. The total electron content (VTEC) in the vertical direction of the monolayer is regarded as a function of latitude and solar time angle. Calculate the location of the puncture point. Based on the satellite observation data received by the receiver over a certain period of time and processed by the TEQC data processing software, the height angle of the satellite is limited and the required data are separated. In order to calculate the coefficients in the polynomial and the total systematic errors which are difficult to eliminate the difference between the formulas, the least square method is used to fit the optimal solutions of these unknown terms, and then the regional ionospheric delay correction model is established. The model is used to calculate the ionospheric delay and compare with the actual delay to verify the effectiveness of the model. Based on the dual-frequency measurements, the electron content above the puncture point is accurately determined, and the coefficients in the polynomial model are used to establish the regional ionospheric delay correction model, which can solve the local ionospheric delay. The correction effect of the polynomial model to the real ionospheric delay is compared with the practical application examples. The advantages of the model are verified. It is shown that the polynomial model is more specific and specific. However, the inborn condition of establishing the model also limits the deficiency of this model in predicting the ionospheric delay. Comparing the advantages and disadvantages of the model, the regional polynomial ionospheric delay correction model based on the GPS dual-frequency observations can improve the measurement accuracy of GPS. It also makes GPS more widely used in height control measurement.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P228.4
【参考文献】
相关期刊论文 前2条
1 刘旭春;李维功;杨军;;GPS硬件延迟计算精度及其稳定性分析[J];测绘科学;2008年05期
2 张小红,李征航,蔡昌盛;用双频GPS观测值建立小区域电离层延迟模型研究[J];武汉大学学报(信息科学版);2001年02期
，本文编号：2223837
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