检索结果-南通市图书馆

第十一届中国卫星导航年会

作者： Qingrui Tao Xiaolin Jia Maosen Hao Lijun Wang Chang’an University Xi’an Research Institute of Surveying and Mapping

Geomagnetic storms are a common natural phenomenon caused by solar activity and other factors, which are closely related to human production activities. In this paper, four ionospheric models during g

关键词： Geomagnetic storm ionospheric model Correction rate

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Application of Compass ionospheric model in GNSS Positioning

Application of Compass Ionospheric Model in GNSS Positioning

引用

第三届中国卫星导航学术年会

作者： Wu XiaoLi1Hu XiaoGong2 .Wang Gang1*Zhong HuiJuan3&Tang ChengPan21. Beijing Global Information Center of Application and Exploration, Beijing 100094, China 2. Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China 3. China Defense Science Technology Information Center, Beijing 100142, China

As an important component of a GNSS navigation message, ionospheric delay model parameters are broadcasted for single-frequency users to improve their positioning accuracy. GPS provides daily Klobuchar ionospheric model parameters based on geomagnetic reference frame, while the regional satellite navigation system of Compass broadcasts an eight-parameter ionospheric model generated by processing real data from continuous monitoring stations, which is updated every 2 hours. To evaluate model performance, model predictions are compared against real ionosphere measurements, along with positioning accuracy comparisons. Real data analysis indicates that the Compass ionospheric model provides higher correction precision in middle-latitude regions, but relatively lower correction precision for low-latitude regions where ionosphere possesses much more variability. Thanks to the constellation design of Compass, ionospheric model errors for some receivers manifest a common bias for in-coming GNSS signals from different satellites. Consequently, ionospheric model errors are somehow translated into the receivers’ clock error estimation, while have less influence on the positioning. Given that the Chinese global navigation system will still rely on a domestic continuous monitoring network to provide global ionosphere correction service, the applicability of the ionospheric model in regions beyond China’s mainland is studied by applying the regional model to single-frequency positioning experiments of GPS. Real data analysis shows that in the northern hemisphere areas including Asia, Europe and North America, compared with the GPS single-frequency positioning using Klobuchar model for ionospheric delay corrections, the three-dimension position accuracy is improved by 7.8% 35.3% by using the Compass model. But the positioning accuracy in the southern hemisphere is degraded by 9.5%3.5% due to the lack of monitoring stations there.

关键词： ionospheric model regional satellite navigation system model error positioning error

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Analysis on correction accuracy of ionospheric model for Beidou system

Analysis on correction accuracy of ionospheric model for Bei...

引用

第五届中国卫星导航学术年会

作者： Wenjun Zhao Qing Gao Daliang Gong P.O. Box 5128 Beijing 100094 China

ISBN: (纸本)9783642547362

With The ionospheric error is the main error sources affecting positioning accuracy for single‐frequency users *** of ionospheric model are broadcast by satellite navigation systems for users,so the correction accuracy of the model has a direct impact on positioning *** on continuous monitoring stations,Beidou system calculated and broadcast 8 parameters of Klobuchar under the geographic coordinate system,and they are updated every 2 *** order to scientifically evaluate the correction effect of Beidou ionospheric model,firstly,the ionospheric model accuracy of different time periods and different latitudes was analyzed through the basis of GIM model provided by CODE based on Beidou latest ***,the following positioning modes were calculated respectively.（1） Single frequency positioning without ionospheric corrections of Beidou.（2） Beidou Single‐frequency + Beidou K8 model.（3） Beidou Single‐frequency + GPS K8 *** effect of residual ionospheric corrections was analyzed for positioning *** results show that the northern hemisphere is better than the southern hemisphere for the accuracy of Beidou ionospheric ***‐latitudes regions can get the best correction,and the RMS of correction residuals was average about 0.6 meters,and it showed a decreasing trend to the low‐latitude and high‐latitude *** K8 model is better than GPS K8 model for single frequency positioning in Beijing.

关键词： ionospheric model regional navigation system correction residuals correction rate

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Global ionospheric Total Electron Content Prediction Based on Spatiotemporal Network model

Global Ionospheric Total Electron Content Prediction Based o...

引用

第十三届中国卫星导航年会

作者： Hongyue Wang Xu Lin Qingqing Zhang Changxin Chen Lin Cheng Zhen Wang College of Earth Sciences Chengdu University of Technology

ionospheric delay is an important source of error in the Global Navigation Satellite System, and the ionosphere total electron content（TEC）, as an important parameter describing the ionospheric properties, directly affects the magnitude of the ionospheric delay. Accurate modeling and forecasting of ionospheric TEC can serve to correct ionospheric delay and improve the accuracy of satellite navigation positioning. However, most of the current ionospheric TEC forecasting studies are only related to the temporal or spatial dimensions, without combining the temporal and spatial information of the global ionospheric TEC, ignoring the spatial and temporal autocorrelation, which seriously limits the forecast accuracy of the global ionospheric TEC. Therefore, we construct a spatiotemporal network forecast model with convolutional long short-term memory with spatiotemporal memory to achieve spatiotemporal forecasting of global ionospheric TEC by learning the temporal variation characteristics and spatial features of global ionospheric TEC and further suppresses the gross error and noise in ionospheric TEC data by using Huber loss function to improve the forecast accuracy of global ionospheric TEC. Compared with the one-day forecasts of global ionospheric TEC from the convLSTM model and the CODE’s spherical harmonic model, the average RMSE of the forecast results of our method is improved by 13.65% and 13.96%, respectively, which can be effectively applied to ionospheric delay error correction and improve the accuracy of satellite navigation and positioning.

关键词： ionospheric total electron content prediction ionospheric model Deep learning Spatiotemporal information Spatiotemporal network

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

SIS accuracy and service performance of the BDS-3 basic system

引用

Science China(Physics,Mechanics & Astronomy) 2020年第6期63卷 105-116页

作者： JinPing Chen XiaoGong Hu ChengPan Tang ShanShi Zhou YuFei Yang JunYang Pan Hui Ren YueXin Ma QiuNing Tian Bin Wu Yang Yu Beijing Satellite Navigation Center Beijing 100094China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Shanghai Key Laboratory for Space Positioning and Navigation Shanghai 200030China

On December 27,2018,the basic system of the third-generation BeiDou navigation satellite system(BDS-3)completed the deployment of its constellation of 18 MEO networking satellites as well as the construction of the operation control system(OCS)and began to provide basic navigation services to users *** with BDS-2,BDS-3 aims to offer users better navigation signals and higher precision with a series of new *** example,the spaceborne atomic clock of BDS-3 is upgraded for higher performance,the Ka-band inter-satellite link is adopted for inter-satellite ranging and communication,and new B1C and B2a signals are broadcast in addition to B1I and B3I signals(compatible with BDS-2).In addition,a 9-parameter model based on a spherical harmonic function is employed for ionospheric delay *** the observation data from 18 satellites of the basic system,this paper conducts a comprehensive evaluation of the pseudorange measurement characteristics,signal-in-space(SIS)accuracy of navigation messages and global service capability of *** results indicate that the pseudorange measurement multipath effect and observation noise of BDS-3 satellites are better than those of BDS-2;additionally,with the support of inter-satellite links,the user range error(URE)of the BDS-3 satellite broadcast ephemeris is better than 10 cm,the precision of the broadcast clock parameter is better than 1.5 ns,and the SIS accuracy is better than 0.6 m *** from the traditional Klobuchar model,the BeiDou global broadcast ionospheric delay correction model(BDGIM)can provide ionospheric delay corrections better than 70%for worldwide single-frequency *** service capability evaluation of the basic system consists mainly of the accuracy improvement of the B1I and B3I signals according to BDS-2 as well as the global positioning accuracy of the new *** results prove that the BDS-3 basic system has achieved the design goal;that is,both the hori

关键词： BDS-3 SIS URE multipath effect broadcast ephemeris broadcast clock ionospheric model positioning accuracy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Principle and performance of BDSBAS and PPP-B2b of BDS-3

引用

Satellite Navigation 2022年第1期3卷 25-33,I0002页

作者： Yuanxi Yang Qun Ding Weiguang Gao Jinlong Li Yangyin Xu Bijiao Sun State Key Laboratory of Geo-Information Engineering Xi’an 710054China Xi’an Research Institute of Surveying and Mapping Xi’an 710054China The 20th Research Institute of China Electronics Technology Group Corporation Xi’an 710054China Satellite Navigation Laboratory Beijing Institute of Tracking and Telecommunication TechnologyBeijing 100094China Beijing Satellite Navigation Center Beijing 100094China.

Within the framework of diferential augmentation,this paper introduces the basic technical framework and performance of the BeiDou Global Navigation Satellite System(BDS-3)Satellite-Based Augmentation System(BDSBAS),including orbit products,satellite clock ofset products,ionosphere and its integrity *** basic principle of BDS-3 Precise Point Positioning(PPP-B2b)is expounded,the similarities and diferences between the PPP service provided by BDS-3 and International Global Navigation Satellite System(GNSS)Service(IGS)are discussed,and the limitations of PPP-B2b are *** both the BDSBAS and PPP-B2b utilize a ground monitoring station network to determine the satellite orbits and clock ofset corrections,and broadcast diferential corrections through the three Geostationary Orbit(GEO)satellites of BDS-3,the feasibility of the co-construction of BDSBAS and PPP-B2b is analyzed,strategies for the infrastructure sharing and correction broadcasting are presented,and the infuences of BDSBAS correction broadcasting strategy adjustment are *** addition,it assesses the possibility of broadcasting diferential corrections through the Inclined Geosynchronous Orbit(IGSO)satellites of BDS-3,and the feasibility of augmenting satellite navigation with Low Earth Orbit(LEO)satellites.

关键词： Satellite-based augmentation Precise point positioning Precise orbit Precise clock ofset ionospheric model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Simulation Study of Ionization Depletion in the Auroral ionospheric F-Region Caused by Strong Convection Electric Field

引用

Wuhan University Journal of Natural Sciences 2001年第3期6卷 680-686页

作者： Cai Hong-tao Ma Shu-ying G. Kirchengast College of Electronic Information Wuhan University Wuhan 430072 China

THe effects of strong convection electric field on the electron density in the auroral ionosphericF-region have been simulated numerically by means of a physical model. It is found that an enhancement of electric field directed west-northward in post-noon or west-southward in pre-noon results in an ionization depletion with its maximum at altitudes 40–50 km higher than that of theF 2 peak. When the enhanced electric field lasts for 45 min and has a maximum about 32 mV/m, the resulted ionization depletions reach their maximum at the time just ～10 min behind the time when the convection electric field and ion temperature enhancements reach their maximum. This is consistent well with EISCAT observations. The magnitudes of the percentage ionization depletions and their recovery time are dependent not only on the intensity of the electric field, but also on the diurnal variation phase of the background electron density.

关键词： auroral ionosphere ionospheric model numerical simulation convection electric field ionization depletion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：