检索结果-南通市图书馆

维普期刊数据库

基于地球GNSS和导航增强星的地月空间导航方法

在线全文

学校读者我要写书评

暂无评论

中国空间科学技术（中英文） 2024年第3期44卷 69-79页

作者：同钊朱向鹏陈素芳徐连军蒙艳松中国空间技术研究院西安分院西安710000

针对载人登月及无人月球探测后续任务中亟须突破的高精度实时自主导航需求,拥有GNSS自主导航能力具有重大意义,符合未来月球探测任务简便、低代价导航发展趋势。而将地球GNSS导航直接应用到地月空间导航场景所能提供的实时导航能力有限... 详细信息

针对载人登月及无人月球探测后续任务中亟须突破的高精度实时自主导航需求,拥有GNSS自主导航能力具有重大意义,符合未来月球探测任务简便、低代价导航发展趋势。而将地球GNSS导航直接应用到地月空间导航场景所能提供的实时导航能力有限,无法满足高精度导航应用的需求。因此,提出了一种基于地球GNSS和导航增强星的地月空间导航方法,通过仅增加一颗月球空间导航节点,在播发导航信号的同时,分别建立与地球GNSS导航星座和月球用户之间的双向时间同步链路,将钟差与位置误差进行解耦,实现月球用户的高精度实时三维绝对导航。仿真结果表明,该方法能大幅提升月球用户的几何精度因子,可获得优于50m的实时定位精度,具有很强的实用性。

关键词：月球导航 GNSS导航月球导航增强卫星双向时间同步钟差解耦实时高精度

维普期刊数据库博看期刊

Analysis Method for GNSS Signal Quality Based on Constellation Diagram

在线全文

学校读者我要写书评

暂无评论

Analysis Method for GNSS Signal Quality Based on Constellati...

Design and test of HiSGR: a novel GNSS/INS ultra tight coupled receiver

第五届中国卫星导航学术年会

作者： Wang Ying Su Zhe meng yansong Tao Xiaoxia China Academy of Space Technology（Xi’an）

ISBN: (纸本)9783642547362

Modern Global Navigation Satellite System（GNSS） signals commonly use very complex modulation and combining method to get diversified and high quality service of navigation,positioning and timing.For that reason,analysis methods of communication signal are not sufficient to reflect navigation signal quality.Based on the analysis of differences between navigation signal and general communication signal,this paper noted concerns and research method of constellation diagram,through real signal generation system,analysed the differences between real signal and ideal signal,proved the method is intuitive and credible through other signal quality analysis methods,and can display more problems of signal generation system and signal quality.

关键词： constellation diagram satellite navigation signal quality

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

Journal of Communications and Information Networks 2016年第3期1卷 67-76页

作者： WANG Xiaoliang WANG Yanguang SU Zhe meng yansong GONG Deren Institute of Satellite Navigation and Intra-Satellite-Link Technology Academy of Space Electrical Information TechnologyXi'an 710100China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200230China

With the support of the national nature science foundation,the Academy of Space Electronic Information Technology is developing a novel compact spaceborne GNSS receiver,referred to as the HiSGR(High Sensitivity GNSS Receiver).This receiver can operate effectively in the full range of Earth orbiting missions,from LEO(Low Earth Orbit)to geostationary and beyond.Improved signal detection algorithms are used in the signal process section of the HiSGR and an inertial sensor is used for GNSS/INS ultra tight coupled design,which makes the acquisition process fast and provides improved tracking performance for weaker GPS signals in the presence of high dynamics.Extensive tests are performed using the HiSGR to demonstrate the good performance of some crucial specifications,by employing a real GNSS signal received in an open field and through hardware-in-the-loop simulation.Receiver performance is demonstrated for LEO and GEO scenarios.A ground vehicle running test is performed for demonstration of fast acquisition and reacquisition capabilities under conditions of signal loss.The HiSGR showed good performance and it was stable during the simulations and tests,which proved its capability for future space applications.

关键词： high sensitivity GNSS/INS ultra tight coupled spaceborne receiver

Strategy of preparing SmCo based films with high coercivity and remanence ratio achieved by temperature and chemical optimization

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

Journal of Rare Earths 2024年第7期42卷 1289-1297页

作者： yansong Gong Zhaoguo Qiu Sizhe Liang Xinrui Zheng Hongxia meng Zhigang Zheng Deyang Chen Shengfu Yuan Weixing Xia Dechang Zeng J.P.Liu School of Materials Science and Engineering South China University of Technology Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong) Co.Ltd. Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal University Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys Laboratory Laboratory of Rare-Earth Magnetic Functional Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of Sciences Department of Physics University of Texas at Arlington

SmCo based films with excellent intrinsic magnetic properties have promising applications in microelectro-mechanical system（MEMS）.However,due to the complexity of phase composition and uncontrollable crystallization degree of SmCo hard magnetic phase in the film,both the coercivity（Hc） and remanence（Mr） of films are difficult to enhance simultaneously.In this paper,SmCo based films were deposited with a Cr underlayer and capping layer on single crystal Si substrates via magnetron sputtering process.The effects of annealing parameters and Sm/Co atomic ratio on the phase structure and coercivity of films are discussed.By adjusting the Sm/Co atomic ratio from 1:5 to 1:4,Co soft magnetic phase disappears and the single phase SmCo5is obtained,leading to the increase of coercivity of the films from30 to 34 kOe.The influence of deposition temperature and Cu doping on magnetic properties of SmCo based films was investigated.When the deposition temperature increases from room temperature to250℃,the coercivity will further increase from 34 to 51 kOe.However,a severe kink is observed in the demagnetization curves due to the poor exchanged coupling.An analysis of transmission electron microscopy（TEM） confirms that the average size of non-hard magnetic amorphous phase exceeds the effective exchanged coupling length of SmCo5,which contributes to the decoupling and low remanence ratio.Therefore,doping Cu and applying a post-annealing process can significantly improve the crystallization degree of the films.Both the coercivity and the remanence ratio of the demagnetization curves are greatly enhanced.We propose a plausible strategy to prepare the SmCo based films with high coercivity and remanence ratio by temperature and chemical optimization,which can be utilized in high performed MEMS devices.

关键词： Coercivity Crystallization conditions Phase composition Rare earths Remanence ratio SmCo based films

Experiment and validation system forX-ray pulsar-based navigation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Experiment and validation system forX-ray pulsar-based navig...

第四届中国卫星导航学术年会

作者： Su Zhe meng yansong Xu Qibing Wang Xiaoliang Feng Xingang Academy of Space Information System

Due to the huge costs, space flight experiment cannot be realized in the preliminary step of X-ray pulsar based navigation （XPNAV） research. So, a kind of XPNAV experiment and 1 validation system is designed in this paper. This system is composed of two parts: the simulation of the pulsar signals and the calculation of navigation parameters. In the first part, the time at which X-ray photon arrive the solar system barycentre is modelled by non-homogeneous Poisson process, then the output pulse of X-ray detector while the observation of pulsars can be simulated by time transformation. In the second part, navigation information included in the pulsar signals which are simulated in the first part can be reached using the Delta-Correction method. This system can simulate four pulsar signals and the process of XPNAV at photo level. This system has the advantage of low costs and high simulation accuracy, and provides a reference for the design of prototype for space flight experiments.

关键词： pulsar navigation experiment and validation system non-homogeneous Poisson process time transfer

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

北斗卫星自主完好性监测及在轨性能评估

Aerospace China 2020年第4期21卷 42-49页

作者： BIAN Lang LIU Xiao LIU Wenshan YAN Tao LEI Wenying JIA Yizhe meng yansong ZHANG Lixin China Academy of Space Technology(Xi’an) Xi’an 710100

With the development of satellite navigation technology,the user demands for the integrity of Global Navigation Satellite System(GNSS)have increased more and more.A ground-based monitoring system can hardly report an alarm message to GNSS users during the valid alarming period due to the satellite-Earth propagation delay.It is beneficial to monitor abnormal events and report the corresponding alarms from orbit.Adopting this approach,which is an important feature for future GNSS integrity monitoring,the time needed to provide an alarm is shorter and the system integrity capability is strengthened.The BeiDou Navigation Satellite System(BDS)new generation satellites have the capabilities of satellite autonomous integrity monitoring(SAIM).This paper presents the technical scheme of SAIM,and proposes the integrity monitoring method of both navigation signals and the clocks onboard.The proposed method was verified through the onboard test on the BDS satellites.In addition,we analyzed the integrity telemetry data from the new generation of BDS satellite,including signal delay,power,carrier phase measurement,correlation peak,consistency of pseudo-code and carrier phase,clock phase and frequency step.The analysis results indicated that the quality of the data on orbit met the requirements,and SAIM could monitor effectively any abnormal change of satellite clocks and navigation signal,generate rapidly an alarm message,and transmit it to the user.The alarm time was less than 6 s through the message,and 2 s through non-standard code(NSC).Finally,we present future opportunities for improving the SAIM technology of BDS.

关键词： SAIM navigation signal satellite clock

维普期刊数据库

Portable solar billboard

在线全文

学校读者我要写书评

暂无评论

Research and Application of Materials Science 2022年第1期4卷 20-23页

作者： Fangyue ZHAO Xinhua YI jia CAI Weishi MA Boyan LIU Xinru LI yansong meng School of Materials Science and Engineering Yingkou University of Technology 115014

Public bulletin boards are widely used in various public places,but due to the large size of the billboards,it is not easy to carry,and the traditional billboards are integrated,when the billboards need to be transferred,the limited storage space of the vehicle needs to be occupied It is extremely inconvenient,and at night,the traditional bulletin boards need to install additional light sources to illuminate them,which greatly increases energy consumption.Based on this paper designed a new structure of the bulletin board,this structure can make the bulletin board when not in use completely folded up and easy to carry,and in use can be completely unfolded and in the bottom of the added retractable support leg structure can be placed anywhere,and according to the terrain or human will to adjust the height.A solar panel is placed on the top of the bulletin board,which can store solar energy during the day and supply energy to the LED lights on the top at night for lighting,which saves energy and is very environmentally friendly.

关键词： Portable solar energy environment protection Billboard

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

基于码片幅度调制的导航信号扩频码认证方法

中国空间科学技术 2023年第1期43卷 69-78页

作者：严涛李天田野王瑛边朗蒙艳松中国空间技术研究院西安分院西安710000

信号认证是满足全球卫星导航系统(GNSS)民用信号安全性需求的关键,相比于导航电文认证(NMA),扩频码认证(SCA)具有更强的安全性。为了在实现SCA的同时不对非认证用户造成影响,提出了一种基于码片幅度调制(CAM)的导航信号SCA方法,对民用... 详细信息

信号认证是满足全球卫星导航系统(GNSS)民用信号安全性需求的关键,相比于导航电文认证(NMA),扩频码认证(SCA)具有更强的安全性。为了在实现SCA的同时不对非认证用户造成影响,提出了一种基于码片幅度调制(CAM)的导航信号SCA方法,对民用信号的扩频码的码片幅度进行了调制,实现了在扩频码层面的认证特征的引入。为了验证所提方法的有效性,采用理论和仿真分析,与GPS L1C采用的Chimera SCA方法进行了比较。结果表明,所提方法在检测性能方面提升了2.55~2.78 dB。研究成果可为下一代高安全卫星导航信号的设计提供支持。

关键词：扩频码认证码片幅度调制检测概率全球卫星导航系统

维普期刊数据库

Global PPP-RTK Method based on GRO and LRO

在线全文

学校读者我要写书评

暂无评论

Global PPP-RTK Method based on GRO and LRO