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Assessment of International GNSS Service Global Ionosphere Map products over China region based on measurements from the Crustal Movement Observation Network of China 被引量:1
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作者 Jin Hu HaiBing Ruan +2 位作者 FuQing Huang ShengYang Gu XianKang Dou 《Earth and Planetary Physics》 EI CAS CSCD 2024年第2期400-407,共8页
The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of G... The global ionosphere maps(GIM)provided by the International GNSS Service(IGS)are extensively utilized for ionospheric morphology monitoring,scientific research,and practical application.Assessing the credibility of GIM products in data-sparse regions is of paramount importance.In this study,measurements from the Crustal Movement Observation Network of China(CMONOC)are leveraged to evaluate the suitability of IGS-GIM products over China region in 2013-2014.The indices of mean error(ME),root mean square error(RMSE),and normalized RMSE(NRMSE)are then utilized to quantify the accuracy of IGS-GIM products.Results revealed distinct local time and latitudinal dependencies in IGS-GIM errors,with substantially high errors at nighttime(NRMSE:39%)and above 40°latitude(NRMSE:49%).Seasonal differences also emerged,with larger equinoctial deviations(NRMSE:33.5%)compared with summer(20%).A preliminary analysis implied that the irregular assimilation of sparse IGS observations,compounded by China’s distinct geomagnetic topology,may manifest as error variations.These results suggest that modeling based solely on IGS-GIM observations engenders inadequate representations across China and that a thorough examination would proffer the necessary foundation for advancing regional total electron content(TEC)constructions. 展开更多
关键词 International GNSS service(igs)global Ionosphere Maps(GIM) Crustal Movement Observation Network of China(CMONOC) total electron content(TEC) data assessment
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How Chinese Financial Centers Integrate into Global Financial Center Networks:An Empirical Study Based on Overseas Expansion of Chinese Financial Service Firms 被引量:18
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作者 PAN Fenghua HE Ziyun +2 位作者 Thomas SIGLER Kirsten MARTINUS Ben DERUDDER 《Chinese Geographical Science》 SCIE CSCD 2018年第2期217-230,共14页
The increasing globalization of the Chinese economy has been enabled by both Chinese financial institutions operating globally as well as international firms operating within China. In geographical terms, this has bee... The increasing globalization of the Chinese economy has been enabled by both Chinese financial institutions operating globally as well as international firms operating within China. In geographical terms, this has been organized through a number of strategic cities serving as gateways for the exchange of financial functions, products and practices between China and the global economy. Drawing on location data of financial service firms in China listed on stock exchanges in Shenzhen, Shanghai and Hong Kong, this paper shows that Chinese financial firms are expanding globally and how Chinese financial centers are positioned and connected in the urban networks shaped by these financial service firms. It is found that Hong Kong, China, holds strategic positions in the integration of Chinese cities into global financial center networks, and that establishing a foothold in global financial centers such as New York and London has been a priority for Chinese financial institutions. The increasing capital flows directed by Chinese financial institutionssuggests a shifting global financial geography, with numerous Chinese cities playing increasingly important roles within global financial center networks. 展开更多
关键词 urban networks corporate networks financial service firms global financial centers China
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Re-Evaluation of China's Service Trade Competitiveness: A Global Value Chain Perspective 被引量:2
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作者 Cheng Dazhong Zheng Lekai Wei Ruqing 《China Economist》 2018年第3期14-25,共12页
Based on the Worm Input-Output Database (WIOD), this paper conducts a forward-linkage decomposition of value-added in trade to estimate China's service value-added exports and its service sector's international co... Based on the Worm Input-Output Database (WIOD), this paper conducts a forward-linkage decomposition of value-added in trade to estimate China's service value-added exports and its service sector's international competitiveness during 2000- 2014. Result indicates that during the sample period, China's service exports measured by forward-linkage decomposition method accounted for around 35% in its total export. While the value of services exported directly through the service sector accounted for a falling share, the value of services exported through other sectors represented an increasing share. China ranks second in the world in terms of market share of service exports. However, the revealed comparative advantage (RCA) of China's service exports and export sophistication remains limited. 展开更多
关键词 global value chain service sector competitiveness of service trade trade in value-added(TiVA)
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Precise Point Positioning Technique with IGS Real-Time Service (RTS) for Maritime Applications 被引量:2
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作者 Mohammed El-Diasty Mohamed Elsobeiey 《Positioning》 2015年第4期71-80,共10页
The maritime navigation accuracy requirements for radionavigation systems such as GPS are specified by the International Maritime Organization (IMO). Maritime navigation usually consists of three major phases identifi... The maritime navigation accuracy requirements for radionavigation systems such as GPS are specified by the International Maritime Organization (IMO). Maritime navigation usually consists of three major phases identified as Ocean/Coastal/Port approach/Inland waterway, in port navigation and automatic docking with an accuracy requirement that ranges from 10 m to 0.1 m. With the advancement in autonomous GPS positioning techniques such as Precise Point Positioning (PPP) and with the advent of the new IGS-Real-Time-Service (RTS), it is necessary to assess the possibility of a wider role of the PPP-based positioning technique in maritime applications. This paper investigates the performance of an autonomous real-time PPP-positioning solution by using the IGS- RTS service for maritime applications that require an accurate positioning system. To examine the performance of the real-time IGS-RTS PPP-based technique for maritime applications, kinematic data from a dual frequency GPS receiver is investigated. It is shown that the real-time IGS-RTS PPP-based GPS positioning technique fulfills IMO requirements for maritime applications with an accuracy requirement ranges from 10 m for Ocean/Coastal/Port approach/Inland waterways navigation to 1.0 m for in port navigation but cannot fulfill the automatic docking application with an accuracy requirement of 0.10 m. To further investigate the real-time PPP-based GPS positioning technique, a comparison is made between the real-time IGS-RTS PPP-based positioning technique and the real-time PPP-based positioning by using the predicted part of the IGS Ultra-Rapid products and the real-time GPS positioning technique with the Wide Area Differential GPS service (WADGPS). It is shown that the IGS-RTS PPP-based positioning technique is superior to the IGS-Ultra-Rapid PPP-based and WADGPS-based positioning techniques. 展开更多
关键词 Real-Time service RTS MARITIME NAVIGATION igs GPS IMO Ultra-Rapid WADGPS
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The Contribution of the Global Framework for Climate Services Adaptation Programme in Africa (GFCS APA) in National Adaptation Plan (NAP) Process for Tanzania 被引量:1
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作者 Agnes Kijazi Ladislaus Chang’a +3 位作者 Philbert Luhunga Hashim Ng’ongolo Mecklina Merchades Pamela Levira 《Atmospheric and Climate Sciences》 2019年第4期650-661,共12页
This article assesses the contribution of the Global Framework for Climate Services Adaptation Programme in Africa (GFCS APA) in the National Adaptation Plan (NAP) process for Tanzania. Different research project outp... This article assesses the contribution of the Global Framework for Climate Services Adaptation Programme in Africa (GFCS APA) in the National Adaptation Plan (NAP) process for Tanzania. Different research project outputs (field survey and workshop reports) produced during the implementation of GFCS APA are reviewed to assess the contribution of GFCS APA programme in the establishment and implementation of NAP process in Tanzania. It is found that the implementation of GFCS-APA programme in Tanzania has improved the availability, accessibility, and applicability of climate information to different stakeholders. This has in turn attributed to significant use of climate information in planning and decision making in target sectors: agriculture and food security, disaster risk reduction, energy, health and water resource management. This has increased the adaptation capacity of vulnerable communities from the impacts of climate variability and change. Furthermore, it is evident that the aims and objectives of establishments of NAP process in Tanzania have been addressed through implementation of GFCS APA Programme. Moreover, since the GFCS APA in Tanzania is implemented within its five pillars namely: observation and monitoring, research, modeling and prediction, climate information systems, user interface platform and capacity development. The achievement made in each pillar contributed in enhancement of resilience of vulnerable communities to climate variability and change hence addressing the aims and objectives of NAP process in Tanzania. Therefore, it is recommended that achievements of GFCS APA Programme in Tanzania to be used as a guide to the development and implementations of the NAP process in Tanzania. 展开更多
关键词 global Framework for CLIMATE serviceS World Meteorological Organization NATIONAL ADAPTATION PLAN
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The Upgraded CIFTIS As A Platform for Global Service Trade
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作者 Lily Wang 《China's Foreign Trade》 2019年第3期32-33,共2页
The 2019 CIFTIS(China International Fair for Trade in Service)themed on 'openness,innovation,wisdom and integration' has recently closed down in Beijing.This year CIFTIS has been upgraded to national exhibitio... The 2019 CIFTIS(China International Fair for Trade in Service)themed on 'openness,innovation,wisdom and integration' has recently closed down in Beijing.This year CIFTIS has been upgraded to national exhibition and witnessed the signing of 440 project contracts with the total contract value of USD 105.06billion,a record high in the event history.There are 134 projects in foreign countries with total contract value of USD 17.55 billion. 展开更多
关键词 service The Upgraded CIFTIS AS A PLATFORM for global service TRADE service
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A New Approach to Provide Global Certificate Service in Virtual Enterprise
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作者 李彪 Zhang Shensheng 《High Technology Letters》 EI CAS 2003年第1期82-86,共5页
Certificate Authority (CA) is the core of public key infrastructure. However, the traditional structure of CA is either hierarchical or reticular, and none of them is suitable for security require-nients come from the... Certificate Authority (CA) is the core of public key infrastructure. However, the traditional structure of CA is either hierarchical or reticular, and none of them is suitable for security require-nients come from the new trend in enterprise cooperation, namely virtual enterprise (VE). In this paper a new idea - virtual certificate authority (VCA), is proposed, as well as its implemen-tation. The goal of VCA is to provide global certificate service over vital enterprise while keeping CA of each participant intact as much as possible. Unlike PEM, PGP, and BCA, by using secret sharing scheme, virtual CA avoids the need for TTP and supports virtual enterprise's feature of dynamical construction and destruction. 展开更多
关键词 global certificate service virtual enterprise virtual certificate authority
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Global Development of Mobile Value Added Services
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作者 Li Shan (China Academy of Telecommunications Research of Mll, Beijing 100083, China) 《ZTE Communications》 2005年第4期2-5,共4页
With the increasing demand for VAS from the subscribers, mobile operators are making efforts to create more services to promote the continuous development of the non-voice service application. The following three mobi... With the increasing demand for VAS from the subscribers, mobile operators are making efforts to create more services to promote the continuous development of the non-voice service application. The following three mobile VASes are becoming the development focus of operators. 展开更多
关键词 In global Development of Mobile Value Added services VAS UMTS SMS
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Cultivating global health professionals: evaluation of a training course to develop international consulting service competence in China
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作者 Pan Gao Li Guan +7 位作者 Yisi Liu Feifei Liu Wenyuan Yu Xiangyu Li Suyang Liu Yuanan Lu Hao Li Hao Xiang 《Global Health Journal》 2020年第2期51-56,共6页
Background:China’s accelerating development and increasingly important role in global health engagement create a great demand for global health professionals including international consulting experts.This study repo... Background:China’s accelerating development and increasingly important role in global health engagement create a great demand for global health professionals including international consulting experts.This study reported the detailed development and evaluation of an international consulting training for global health workforce.Methods:Based on Kirkpatrick’s model,a mixed-methods approach was used to evaluate the effectiveness of the training.Quantitative and qualitative data on participants’reaction,learning,and application of the learned knowledge and skills were collected by a training evaluation survey at the ending of training and a follow-up interview in three months after the training.Results:Thirty-six participants attended the training and 34 of them completed quantitative investigation.The training satisfaction evaluations were positive,for which participants rated the training program highly and over 90%of them agreed with the usefulness of the training.About knowledge and skills change,participants showed improved consulting knowledge and skills from pre-to post-training(P<0.001).A total of 23 participants accepted follow-up interview,and most participants applied knowledge and skills learned from the training in their daily work or study.However,only 30.4%of participants applied their learning in the consulting program.The largest barrier of application was the lack of consulting opportunities.In addition,almost all the participants reported that they would be glad to attend more training courses in the future.Conclusion:The international consulting training program was well-received,and was feasible to improve the consulting service competence of global health professionals.According to participants’feedback,it is essential to develop and expand consulting training in the field of global health. 展开更多
关键词 Training evaluation SATISFACTION Kirkpatrick’s model global health International consulting service
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Global Business Travel Service
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《China's Foreign Trade》 1995年第3期8-8,共1页
The Global Business Travel Service, a class-1 travel service approved by the National Tourism Adminis-tration (NTA), is affiliated to the China Council for the Promotion of International Trade and the China Chamber of... The Global Business Travel Service, a class-1 travel service approved by the National Tourism Adminis-tration (NTA), is affiliated to the China Council for the Promotion of International Trade and the China Chamber of International Commerce. It mainly serves foreign and domestic organizations and associations of industry and commerce, import and export corporations, 展开更多
关键词 NTA global Business Travel service
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Discussion on the Importance of Legal English under the Background of Globalization of Legal Services
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作者 王萌 《海外英语》 2020年第2期285-286,共2页
Under the background of the internationalization of legal services,the legal relationship is becoming more and more complex in the private international law area.The demand for international legal services for compoun... Under the background of the internationalization of legal services,the legal relationship is becoming more and more complex in the private international law area.The demand for international legal services for compound talents with foreign language as the core is expanding,while the number of transnational legal offices is increasing rapidly.It options a higher demand on the English level of talents involved in transnational legal affairs.This paper tends to analyze the importance of legal English from the perspective of globalization. 展开更多
关键词 legal English globalIZATION transnational legal affairs legal education legal services
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Serving the Global Market with Best Quality and Services
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作者 CNPC’s top management visiting CPTDC’s Booth 《China Oil & Gas》 CAS 2002年第3期32-33,共2页
China Petroleum Technology & Development Corporation (CPTDC), a wholly owned subsidiary company of China National Petroleum Corporation (CNPC), is China's largest multinational company specializing in the manu... China Petroleum Technology & Development Corporation (CPTDC), a wholly owned subsidiary company of China National Petroleum Corporation (CNPC), is China's largest multinational company specializing in the manufacturing and supply of petroleum and petrochemical material, equipment and technology. 展开更多
关键词 CNPC Serving the global Market with Best Quality and services
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ASTM provides world-leading digitalized standards services--Interview with Hu Yanan,Operation Manager of the ASTM International China Office
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作者 Cao Xinxin Hu Yanan 《China Standardization》 2024年第5期22-27,共6页
With a 126-year history,ASTM International still exudes strong vitality today.It is one of the most renowned standards organizations in the world,boasting a globally leading standards development system and database.I... With a 126-year history,ASTM International still exudes strong vitality today.It is one of the most renowned standards organizations in the world,boasting a globally leading standards development system and database.It is open,transparent,fair,diverse,inclusive,and consensus-driven,but these are just some of its characteristics.ASTM always prioritizes the development of standards and the needs of industries and users. 展开更多
关键词 services globally ASTM
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基于全球IGS数据的GPS导航星座精密轨道确定 被引量:8
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作者 盛传贞 袁运斌 +2 位作者 孙保琪 姬张建 肖长伟 《大地测量与地球动力学》 CSCD 北大核心 2011年第1期138-141,共4页
研究GPS导航星座精密轨道确定的基本问题及其处理策略。基于2008年3月29日至4月7日的148个站的IGS站数据,计算了GPS卫星轨道的单天解和3天解,通过与CODE中心的最终轨道进行比较,评价了相应轨道的精度。结果显示,基于该导航星座轨道生成... 研究GPS导航星座精密轨道确定的基本问题及其处理策略。基于2008年3月29日至4月7日的148个站的IGS站数据,计算了GPS卫星轨道的单天解和3天解,通过与CODE中心的最终轨道进行比较,评价了相应轨道的精度。结果显示,基于该导航星座轨道生成策略,单天轨道解径向精度优于9 cm,3天解轨道径向精度优于5 cm。 展开更多
关键词 GPS 全球igs数据 导航星座 精密轨道确定 导航
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IGS精密星历的误差分析 被引量:19
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作者 李鹏 沈正康 王敏 《大地测量与地球动力学》 CSCD 北大核心 2006年第3期40-45,共6页
采用高精度的ITRF2000全球参考框架、新的地球物理模型和误差改正模型、统一的卫星轨道参量和地球自转模型、统一的数据处理策略,重新处理了IGS全球跟踪站数据以求解1994~2004年的GPS卫星轨道。通过轨道比较评估了IGS精密星历的系统偏... 采用高精度的ITRF2000全球参考框架、新的地球物理模型和误差改正模型、统一的卫星轨道参量和地球自转模型、统一的数据处理策略,重新处理了IGS全球跟踪站数据以求解1994~2004年的GPS卫星轨道。通过轨道比较评估了IGS精密星历的系统偏差和随机误差,发现IGS精密星历标称精度和实际精度存在差异,特别是早期结果。IGS精密星历在不同时期存在不同的系统偏差,主要由其在不同时期采用的不同ITRF序列参考框架之间的差异引起,IERS公布的转换参数不能完全表征ITRF序列间的差异。相对于重解精确轨道,IGS精密星历随机误差随时间逐渐减小,1994年为15~20cm,1998年逐渐减小到6~8cm,1998年以后小于5cm。 展开更多
关键词 GPS igs精密星历 误差分析 全球参考框架 IRES
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IGS产品批量、定时、自动下载软件设计与实现 被引量:6
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作者 刘智敏 黄超 +2 位作者 窦世标 张海平 冯彦同 《全球定位系统》 CSCD 2016年第2期110-114,共5页
随着全球GNSS的发展以及IGS自身的不断完善,IGS产品精度不断提高、应用更加广泛,广大用户对IGS产品的要求也在不断增长,下载日益频繁。IGS通过文件传输协议服务实现IGS产品的发布,人工下载步骤烦琐,费时费力且容易出错,文中利用C#语言... 随着全球GNSS的发展以及IGS自身的不断完善,IGS产品精度不断提高、应用更加广泛,广大用户对IGS产品的要求也在不断增长,下载日益频繁。IGS通过文件传输协议服务实现IGS产品的发布,人工下载步骤烦琐,费时费力且容易出错,文中利用C#语言开发了IGS产品的下载软件,实现了相关文件的批量、定时、自动下载,有助于减轻工作人员的负担,提高工作效率,而且能够在文件发布后及时下载,减少错误发生的概率。通过对2015年9月份不同发布周期、不同类型文件的下载,证实了本软件进行IGS产品下载的可行性。 展开更多
关键词 igs产品 定时下载 FTP服务
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IGS快速精密星历与事后精密星历的定位精度分析 被引量:8
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作者 汪平 许家琨 +1 位作者 沈国康 孙雪洁 《海洋测绘》 CSCD 2015年第5期32-34,共3页
针对是否能用IGS快速精密星历代替最终精密星历进行定位的问题,论文通过静态、动态两类实验,从内符合、外符合精度两个方面详细比较了两种星历产品的定位效果。实验结果表明:IGS快速精密星历的定位精度与事后精密星历的定位精度都非常高... 针对是否能用IGS快速精密星历代替最终精密星历进行定位的问题,论文通过静态、动态两类实验,从内符合、外符合精度两个方面详细比较了两种星历产品的定位效果。实验结果表明:IGS快速精密星历的定位精度与事后精密星历的定位精度都非常高,且两种产品对应定位结果差异为毫米级,因此可采用快速精密星历代替事后精密星历进行定位解算,而不必担心精度损失。 展开更多
关键词 igs igs快速精密星历 igs事后精密星历 内符合精度 外符合精度
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IGS实时产品质量分析及其在实时精密单点定位中的应用 被引量:16
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作者 王胜利 王庆 +2 位作者 高旺 潘树国 时小飞 《东南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2013年第A02期365-369,共5页
首先研究了IGS实时卫星轨道和钟差产品的修复方法并对其质量进行了分析,包括实时数据流实时获取的稳定性以及其轨道和钟差产品与IGS最终轨道和钟差产品相比较的精度.在此基础上使用实时轨道和钟差产品对全球分布的179个IGS连续跟踪站进... 首先研究了IGS实时卫星轨道和钟差产品的修复方法并对其质量进行了分析,包括实时数据流实时获取的稳定性以及其轨道和钟差产品与IGS最终轨道和钟差产品相比较的精度.在此基础上使用实时轨道和钟差产品对全球分布的179个IGS连续跟踪站进行了精密单点定位解算实验.分析结果表明,所选取的BKG分析中心提供的实时数据流获取率可达到92.59%,轨道在径向、切向和法向上的精度统计分别为1.90,3.15和2.47 cm,钟差产品的平均RMS可达到0.106 ns.全球分布的179个IGS跟踪站的单天定位解在N/E/U方向上平均定位精度为-3.5/-4.2/-9.mm,中误差达到10.0/15.2/22.9 mm,从而验证了实时轨道和钟差产品可以满足实时PPP厘米级的定位需求的结论. 展开更多
关键词 igs实时试验计划 实时PPP UPthree软件 精度分析
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中国大陆IGS基准站基线时间序列噪声分析 被引量:3
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作者 吉长东 沈祎凡 王强 《导航定位学报》 CSCD 2019年第3期108-114,共7页
针对基线时间序列中信号与噪声难分离的问题,提出一种确定最优噪声模型的方法:利用幂律模型(PLM)与极大似然估计(MLE)相结合的方法,求出3维坐标向量的功率谱指数和最大似然估计值,确定出最优噪声模型;然后利用中国大陆6个IGS站6 a的观... 针对基线时间序列中信号与噪声难分离的问题,提出一种确定最优噪声模型的方法:利用幂律模型(PLM)与极大似然估计(MLE)相结合的方法,求出3维坐标向量的功率谱指数和最大似然估计值,确定出最优噪声模型;然后利用中国大陆6个IGS站6 a的观测数据进行实验。结果表明:基线时间序列存在白噪声(WN)、闪烁噪声(FN)和随机漫步噪声(RWN);N方向的情况为,当基线长度在1 015~2 500 km之间时,主要为WN+FN,当基线长度大于2 500 km且小于3 225 km时,则为WN+FN+RWN,且RWN占43.09%;E和U方向最优噪声模型分别为WN+RWN与WN+FN,并且RWN与FN分别占62.11%和89.88%。 展开更多
关键词 全球卫星导航系统(GNSS) 国际GNSS服务组织(igs)基准站 基线时间序列 谱指数 极大似然估计 噪声模型
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用IGS发布的TEC数据提高法拉第旋转校正精度 被引量:2
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作者 严卫 施健康 陆文 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2010年第3期225-229,共5页
电磁波穿过电离层时引入的法拉第旋转是导致全极化微波辐射计观测亮温产生交叉极化的重要原因.分析得知IRI(international reference ionosphere)模型产生的TEC(totalelectron content)数据在部分低纬地区无法满足全极化辐射计对法拉第... 电磁波穿过电离层时引入的法拉第旋转是导致全极化微波辐射计观测亮温产生交叉极化的重要原因.分析得知IRI(international reference ionosphere)模型产生的TEC(totalelectron content)数据在部分低纬地区无法满足全极化辐射计对法拉第旋转的校正精度要求.为提高校正精度,分析了沿观测路径积分法和应用IGS(International GPS Service)发布的TEC数据校正两种方法对校正精度的影响.结果表明,沿观测路径积分法不能有效改善校正精度,而应用IGS数据校正可大幅提高低纬地区法拉第旋转校正精度,满足全极化微波辐射计对极化旋转角的校正精度要求. 展开更多
关键词 法拉第旋转 全极化微波辐射计 薄层近似 国际GPS服务网 国际参考电离层模型
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