GNSS仿真系统高精度实时区域电离层建模与短期预报研究

发布时间：2018-06-05 15:17

本文选题：电离层 + 全球定位系统　；参考：《电子科技大学》2015年硕士论文

【摘要】：随着现代通信技术的迅猛发展,使得许多科学技术在研究和应用中都必须考虑电离层对无线电波的影响。近年来全球导航卫星系统(GNSS)的应用几乎渗透进了科学研究的各个领域,在研究如何消除GNSS中来自电离层误差的同时,GNSS也为电离层研究提供了一个新的方向。其中在电离层研究中最具代表性的便是GNSS中的全球定位系统(GPS)的应用。针对这种情况,本文利用GPS对高精度实时区域电离层建模与短期预报进行了研究。具体研究内容有四部分:1.研究了电离层的相关特性。由于电离层的内部变化相当复杂,要对电离层进行研究就要了解电离层的相关特性。因此,本文首先研究了电离层的分层结构及其异常现象,并利用实测数据分析了影响电子含量(TEC)的因素。然后介绍了在电离层研究中需要用到的基础知识。2.研究了实时区域高阶电离层延迟模型的建模方法。当前的电离层延迟模型大多仅考虑一阶项的影响,未将高阶项的影响加入模型当中,导致模型的精度无法满足精密测量和定位的需求。针对这种情况,本文分析了电离层高阶项对卫星信号的影响,并利用伪距观测值和多项式函数模型推导出高阶电离层延迟模型的观测方程。同时,对模型建立过程中每个阶段要采用的算法进行了研究和分析,从而保证模型的高精度性和实时性。在求解地磁场矢量时,本文利用曲面拟合方法取代复杂的国际参考地磁场模型计算方法,从而达到了简化计算的目的。在此基础上,最终建立了高阶电离层延迟模型并通过实测数据证明了模型的高精度性。3.研究了基于组合思想的区域电离层短期预报模型的建模方法。作者在传统ARMA模型的基础上提出利用组合预报理论对TEC进行短期预报。针对序列的特性,本文将全年分为四个时段,并选取季节模型和ARMA模型对相应的序列特性进行分析,最终建立了组合预报模型。最后通过实例证明了组合模型的短期预报效果整体优于传统ARMA模型以及所提出的组合预报方法是不受时间和地理位置限制的。4.研究了区域电离层延迟和短期预报仿真软件的设计和开发。该软件为区域高阶电离层延迟的计算和电离层TEC的短期预报提供了方便。
[Abstract]:With the rapid development of modern communication technology, the influence of ionosphere on radio waves must be considered in the research and application of many science and technology. In recent years, the application of GNSS (Global Navigation Satellite system) has penetrated almost every field of scientific research. While studying how to eliminate the errors from ionosphere in GNSS, it also provides a new direction for ionospheric research. The application of GPS (Global Positioning system) in GNSS is the most representative in ionospheric research. In this paper, GPS is used to study the high precision real time ionospheric modeling and short term prediction. There are four parts: 1. The related characteristics of the ionosphere are studied. Because the internal variation of the ionosphere is very complicated, it is necessary to understand the characteristics of the ionosphere in order to study the ionosphere. Therefore, the stratified structure of the ionosphere and its anomalous phenomena are studied in this paper, and the factors affecting the electron content (TECs) are analyzed by using the measured data. Then the basic knowledge used in ionospheric research. 2. 2. The modeling method of high order ionospheric delay model in real time region is studied. Most of the current ionospheric delay models only consider the influence of the first order term, and the influence of the higher order term is not added to the model, which results in the precision of the model can not meet the needs of precision measurement and positioning. In this paper, the influence of ionospheric higher-order terms on satellite signals is analyzed, and the observation equations of higher-order ionospheric delay models are derived by using pseudo-range observations and polynomial function models. At the same time, the algorithms used in each stage of model establishment are studied and analyzed to ensure the high accuracy and real time of the model. In solving the geomagnetic field vector, this paper uses the curved surface fitting method to replace the complicated international reference geomagnetic field model calculation method, thus achieving the purpose of simplifying the calculation. On this basis, the high-order ionospheric delay model is established and the high accuracy of the model is proved by the measured data. The modeling method of regional ionospheric short-term prediction model based on combinatorial theory is studied. Based on the traditional ARMA model, the author proposes to use the combined forecasting theory to predict the TEC in the short term. According to the characteristics of the series, the whole year is divided into four periods, and the seasonal model and the ARMA model are selected to analyze the characteristics of the corresponding sequence. Finally, the combined prediction model is established. Finally, it is proved that the short-term prediction effect of the combined model is better than that of the traditional ARMA model, and that the combined forecasting method is not limited by time and geographical location. The design and development of simulation software for regional ionospheric delay and short term prediction are studied. The software is convenient for the calculation of high-order ionospheric delay and the short-term prediction of ionospheric TEC.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN967.1

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