中国GPS中性大气天顶延迟研究及应用
文献类型:学位论文
作者 | 曲伟菁 |
学位类别 | 硕士 |
答辩日期 | 2007-06-18 |
授予单位 | 中国科学院上海天文台 |
授予地点 | 上海天文台 |
导师 | 平劲松 |
关键词 | Hopfield模型 Saastamoinen模型 EGNOS模型 对流层天顶延迟 |
其他题名 | Studying GPS zenith troposphere delay and the application in China |
中文摘要 | The troposphere ranges from ground level to about 40km in altitude. When GPS signal transmit from the atmosphere to receiver, the signal transmission delay caused by the troposphere can be about 2.3m at the zenith and about 20~25m at lower receiver-to-satellite elevation angles such as 10 degrees. So the troposphere delay is one of the major error sources in GPS /GNSS satellite navigation. For the purposed of application, the character of zenith troposphere delay(ZTD) in the region of China, the evaluate of precision about Hopfield、Saastamoinen and EGNOS tropospheric delay correction model are studied, and the local models of tropospheric delay correction of Chinese S/C tracking station is built in these thesis. The main contents of this thesis as followings: 1 In order to study the ZTD of the region of China, the data of 30 stations from 1999 to 2004 obtained from Crustal Motion Observation Network of China(CMONC) are used. The annual, seasonal, monthly, diurnal and the distribution variations are discussed. The studies show that there is a very strong annual variation, the character of which(the swing and the average) is relate to the latitude and height of stations.; seasonal variation is obviously which is max in summer and min in winter; Through the study of monthly average, the ZTD in the south is bigger than in the north and it in the east is bigger than in the west(the major reason is the hypsography of the west is higher than east); The system differences between the day and the night isn’t obviously. 2 We evaluate the precision about Hopfield、Saastamoinen and EGNOS tropospheric delay correction model using the data of ZTD and meteorology obtained from IGS . The results show that if there is meteorological data, the precision of Saastamoinen model is highest; The precision of EGNOS model is as well as it of Hopfield model and Saastamoinen model. But if there isn’t meteorological data (standard meteorological data), the precision of EGNOS model is better than Hopfield model and Saastamoinen model. So EGNOS model is a good choice if there isn’t real time meteorological data. We also first discovered that the problem of Hopfield model: it isn’t suitable to be used to correct the 3 Because of the need of the EC-1, ,we build a forecasting model on the basis of EGNOS model with the data obtained from COMOC. And then a real-time model is built on the basis of the forecasting model. The newly established model have been successfully tested and confirmed in ESA lunar orbit SMART-1 VLBI observation experiments. |
英文摘要 | 中性大气层是指从地面向上大约到40 范围内的大气层,它可以分成低部的对流层和以上的平流层,有时也统称对流层。GPS卫星信号经过地球的大气层传播至地基GPS接收机时,受到中性大气折射的影响,产生时延和路径弯曲,由此造成信号的传播延迟。天顶方向的中性大气延迟约为2.3 ,当高度角为10度时,此延迟将增加至约20~25 。中性大气延迟是高精度GPS/GNSS定位中误差源之一。本文从实际应用的角度,分析了中国地区天顶延迟变化特征,比较了目前应用较多的几个对流层延迟改正模型的精度和适用性,并由此建立中国VLBI站的单站对流层延迟改正模型。 本论文主要研究内容是: 1. 为了研究中国地区上空的对流层天顶延迟的情况,我们利用地壳运动监测网络1999~2004年中国30个GPS基准站的天顶延迟,进行了中国地区天顶延迟变化特性分析;其中包括年变化、季节变化,月变化、日变化和区域分布的统计分析。结果表明,天顶延迟变化有很强的周年性,其年变化特性(如周年变化的振幅,年均值)与台站的纬度和高程相关。天顶延迟在不同季节之间的变化也比较明显,夏季达到最大值,冬季达最小值;通过天顶延迟月平均值的分析,发现中国天顶延迟南部大于北部,东部大于西部(其主要原因是,我国西部的地势高于东部,东部湿度大于西部);天顶延迟白天与晚上差值无明显的系统偏差。 2. 利用IGS提供的2003年的天顶延迟和实测气象数据,对目前国际上用的几个天顶延迟模型进行了精度和适用程度的评估,包括气象数据的Hopfield模型和Saastamoinen模型(实测气象参数和标准气象参数两种情况)以及不需要实测气象参数的EGNOS模型。通过比较分析,结果表明,对实测气象数据,Saastamoinen模型精度最高;EGNOS模型与Hopfield模型基本相当,它们与Saastamoinen模型差别并不显著。而在没有实测气象数据(即用标准气象数据)的情况下,EGNOS模型的精度优于Hopfield和Saastamoinen模型。在实际应用中,对没有实测气象数据,又要获得具有一定精度的对流层延迟改正的情况,采用EGNOS模型应是较好的选择。通过比较分析,发现了Hopfiled模型存在的问题:不适用于高度较高的测站高精度天顶延迟的改正。 3. 针对探月工程任务大气延迟改正的需求,利用地壳运动网多年的GPS天顶延迟值,并参照EGNOS模型建立了中国VLBI站的预报模型,并在预报模型基础上利用实测气象数据建立了实时模型。在2006年夏季的观测实验中,预报模型已经被用于观测任务中,满足工程任务的要求。 |
语种 | 中文 |
公开日期 | 2011-07-01 |
页码 | 68 |
源URL | [http://119.78.226.72//handle/331011/14610] ![]() |
专题 | 上海天文台_中国科学院上海天文台学位论文 |
推荐引用方式 GB/T 7714 | 曲伟菁. 中国GPS中性大气天顶延迟研究及应用[D]. 上海天文台. 中国科学院上海天文台. 2007. |
入库方式: OAI收割
来源:上海天文台
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