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Development trends of the national secure PNT system based on BDS

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Science China Earth Sciences 2023年第5期66卷 929-938页

作者： Yuanxi YANG Xia REN xiaolin jia Bijiao SUN State Key Laboratory of Geo-Information Engineering Xi’an 710054China Xi’an Research Institute of Surveying and Mapping Xi’an 710054China

Satellite navigation systems are *** guarantee the positioning,navigation and timing(PNT)safety of core infrastructure,it is necessary to establish a secure PNT system with hybrid physical *** this paper,the augmentations of the BeiDou satellite system(BDS)itself are analysed,namely augmentations through the BDS inter-satellite link,BDS geostationary orbit(GEO)and inclined geostationary orbit(IGSO)satellites,and BDS PNT services supported by low earth orbit(LEO)***,taking BDS as the core component,the comprehensive PNT infrastructure seamlessly covering deep space and deep ocean is described,consisting of the deep space PNT constellation,the sea-floor PNT sonar beacon network,and the ground-based low frequency and very low frequency(VLF)long wave radio ***,the key technologies of resilient PNT application matching comprehensive PNT and various autonomous perception PNT information are discussed,such as resilient PNT sensor integration,the resilient PNT functional model and the resilient stochastic *** a future development direction,the key factors of intelligent PNT services are analysed,including the intelligent perception of PNT application scenes,the intelligent optimization of PNT functional and stochastic models and the intelligent fusion of multisource PNT information.

关键词： Secure PNT system Comprehensive PNT infrastructure Resilient PNT application Intelligent PNT application

Analysis and design for architecture-based software

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Journal of Systems Engineering and Electronics 2005年第4期16卷 924-930页

作者： jia xiaolin He jian Qin Zheng Wang Xianghua School of Electronics and Information Xi'an Jiaotong Univ. Xi'an 710049 P. R. China

The technologies of software architecture are introduced, and the software analysis-and-design process is divided into requirement analysis, software architecture design and system design. Using these technologies, a model of architecture-centric software analysis and design process（ACSADP） is proposed. Meanwhile, with regard to the completeness, consistency and correctness between the software requirements and design results, the theories of function and process control are applied to ACSADP. Finally, a model of integrated development environnment （IDE） for ACSADP is propcsed. It can be demonstrated by the practice that the model of ACSADP can aid developer to manage software process effectively and improve the quality of software analysis and design.

关键词： software process software architecture design space traceability.

Uncombined precise orbit and clock determination of GPS and BDS-3

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Satellite Navigation 2020年第1期1卷 206-216页

作者： Tian Zeng Lifen Sui Rengui Ruan xiaolin jia Laiping Feng Information Engineering University Zhengzhou 450001People’s Republic of China State Key Laboratory of Geo-Information Engineering Xi’an 710054People’s Republic of China Xi’an Research Institute of Surveying and Mapping Xi’an 710054People’s Republic of China

There is increasing concern about the uncombined(UC)observation model in the field of global navigation satellite system(GNSS).Based on the global positioning system(GPS)and the third-generation BeiDou navigation satellite system(BDS-3),this study processed the UC precision orbit determination(POD)for single and dual ***,a UC observation model suitable for multi-GNSS POD was derived,and the ionospheric-free(IF)combination observation model was *** the ambiguity parameters of UC and IF strategies were different after reparameterization,the difference could be removed when processing ambiguity resolution,and the equivalence was proved *** demonstrate the accuracy of BDS-3 orbits fully,the observation data of approximately 1 month were selected for determining the precise orbit for global positioning system(GPS)only,BDS-3 only,and GPS/BDS-3 systems based on the UC and IF *** orbit precision of BDS-3 satellites was validated by using metrics,including comparison with precision products released by Wuhan University,orbit boundary discontinuity,and satellite laser ranging(SLR)*** results show that the orbit accuracies of the IF and UC models are almost the same,the difference in orbits is approximately several millimeters,and the clock difference is within 0.01 *** GPS/BDS-3 combined solution shows better accuracy compared to other *** average accuracies in the R and 3D directions are approximately 4 and 15 cm,and the clock standard deviation is approximately 0.2 ns compared to external orbit *** root mean square of SLR residuals is approximately 4 cm.

关键词： Precise orbit determination GPS BDS-3 Uncombined model Ionospheric-free combination

Analysis of error sources on orbital atomic clocks’stability

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Geo-Spatial Information Science 2012年第3期15卷 207-211页

作者： MAO Yue CHEN jianpeng DAI Wei jia xiaolin State Key Laboratory of Geo-Information Engineering Xi’an 710054China Xi’an Research Institute of Surveying and Mapping Xi’an 710054China State Bureau of Surveying and Mapping Key Laboratory for Polar Surveying and Mapping Science Wuhan 430079China

As a rule,stability calculation of atomic clock requires observations with equivalent sampling *** from atomic clocks in laboratory,orbital atomic clock stability calculations are impacted of raw data sampling intervals,noncontinuous time series,non-data segment,frequency drift,and other ***,the calculated stability results are not so *** this article,the impacts of kinds of error sources on Allan and Hadamard variances are analyzed using global positioning system satellite precise clock offset *** the laws of variety are summarized.

关键词： atomic clocks Allan variance Hadamard variance frequency drift

GEO and IGSO joint precise orbit determination

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Science China(Physics,Mechanics & Astronomy) 2011年第6期54卷 1009-1013页

作者： MAO Yue DU Yu SONG XiaoYong jia xiaolin WU XianBing Xi'an Research Institute of Surveying and Mapping Xi'an 710054China China Aerospace Science and Technology Corporation Beijing 100048China

Experiments and analyses are carried out for GEO and joint GEO/IGSO precise orbit determination using data recorded by China's regional tracking *** show that joint GEO/IGSO orbit determination effectively solves the problem of poor observation geometry for GEO *** laser radial evaluation thus confirms that precision is as good as less than 0.1 *** the case of joint orbit determination,solving the empirical acceleration can reduce errors introduced by the imprecise solar radiation pressure model used for Chinese *** method also improves the accuracy of orbit prediction in the radial *** ephemeris accuracy is thus improved and the ephemeris can provide a better service to users with navigation and positioning requirements.

关键词： precise orbit determination empirical acceleration regional tracking network GEO IGSO

Demand and key technology for a LEO constellation as augmentation of satellite navigation systems

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Satellite Navigation 2024年第1期5卷 1-9页

作者： Yuanxi Yang Yue Mao Xia Ren xiaolin jia Bjiao Sun Xi’an Research Institute of Surveying and Mapping Xi’an710054ShaanxiChina State National Key Laboratory of Geo-Information Engineering Xi’an710054ShaanxiChina

A Low Earth Orbit(LEO)constellation augmenting satellite navigation is important in the future development of Global Navigation Satellite System(GNSS).GNSS augmented by LEO constellations can improve not only the accuracy of Positioning,Navigation,and Timing(PNT),but also the consistency and reliability of secure PNT *** paper mainly analyzes the diverse demands of different PNT users for LEO augmented GNSS,including the precision demand in real-time,the availability demand in special areas,the navigation signal enhancement demand in complex electromagnetic environments,and the integrity demand with high ***,the possible contributions of LEO constellations to PNT performance are analyzed from multiple aspects.A particular attention is paid to the special PNT user requirements that cannot be fulfilled with existing GNSS,such as the PNT service demand in the polar regions and the onboard GNSS orbit determination demand of some LEO *** key technologies to be considered in the constellation design,function realization,and payload development of the LEO-augmented navigation system are summarized.

关键词： Low earth orbit navigation constellation Accuracy augmentation Orbit determination Integrity

Influence of Crucible Material on the Microstructure and Properties of Iron Rich Glass-Ceramics

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Journal of Wuhan University of Technology(Materials Science) 2018年第1期33卷 49-55页

作者：邓磊波张雪峰 LI Baowei jia xiaolin ZHANG Mingxing OUYANG Shunli Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and Technology School of Mathematics Physics and Biological Engineering Inner Mongolia University of Science &Technology School of Material Science and Engineering Zhengzhou University

Slag glass melting is usually performed on a laboratory scale in crucibles, which are economically viable tools for the production of slag glass-ceramics. In this work, quaternary CaO-Al2O3-MgO-SiO2（CAMS） glass-ceramics were prepared by melting the tailing of Bayan Obo mine tailing, blast furnace slag, and fly ash in alumina and graphite crucibles. The effect of the crucible material on the microstructure and properties of the glass-ceramics was investigated using differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and inductively coupled plasma atomic emission spectroscopy. Results indicated that the contents of Al2O3 and Fe2O3 in the initial glass were significantly changed by the corrosion of the alumina crucibles during the glass melting process and by the reducing action of the graphite crucibles. The main crystal phases of glass-ceramics melted in alumina crucibles and graphite crucibles were Ca（Mg, Fe, Al）（Si, Al）2O6, coesite and Ca（Mg, Al）（Si, Al）2O6, respectively. According to these findings, we conclude that the microstructure and properties of the glass-ceramics are affected by the crucibles.

关键词： slag glass-ceramics graphite crucible alumina crucible

Orbit determination and time synchronization for BDS-3 satellites with raw inter-satellite link ranging observations

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Satellite Navigation 2020年第1期1卷 81-92页

作者： Rengui Ruan xiaolin jia Laiping Feng Jun Zhu Zongbo Huyan Jie Li Ziqing Wei Xi’an Research Institute of Surveying and Mapping Xi’an 710054China State Key Laboratory of Geo-information Engineering Xi’an 710054China Information Engineering University Zhengzhou 450001China China Xi’an Satellite Control Center Xi’an 710043China State Key Laboratory of Astronautic Dynamics Xi’an 710043China

To provide competitive global positioning and timing services under the condition that monitoring stations are confined to Chinese territory,inter-satellite link(ISL)technology is used by the third-generation BeiDou Navigation Satellite System(BDS-3).The ISL,together with the dual one-way links between satellites and anchor stations,may enable autonomous navigation for *** this paper,we propose a general observation model for orbit determination(OD)and time synchronization(TS)directly using non-simultaneous observations,such as raw ISL *** the proposed model,satellite orbits,clocks,and hardware delay biases of ISL equipment can be determined simultaneously by jointly processing inter-satellite one-way pseudorange data and observation data from ground monitoring ***,autonomous OD and TS are also achievable with one-way pseudorange data from anchor stations and *** from eight BDS-3 satellites,two anchor stations,and seven monitoring stations located in China were collected to validate the proposed *** is shown that by jointly processing data from the ISL and seven monitoring stations,the RMS of overlap orbit differences in radial direction is 0.019 m,the overlap clock difference(95%)is 0.185 ns,and the stability of the estimated hardware delay biases for each satellite is greater than 0.5 *** with the results obtained with the seven stations,the improvements of orbits in radial direction and clocks are 95.7%and 90.5%,*** the hardware delay biases are fixed to predetermined values,the accuracies of orbits and clocks are further *** jointly processing pseudoranges from the satellites and the two anchor stations,the RMS of overlap orbit differences is 0.017 m in the radial direction,and the overlap clock difference(95%)is 0.037 *** has also been demonstrated that under the condition of one-way ranging links,the accuracies of orbits and clocks obtained by the above two modes are still signi

关键词： BDS-3 Inter-satellite link Anchor station Orbit determination Time synchronization Hardware delay bias

Fast Measurement of Absorbing Performances of Additives

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材料保护 1991年第11期 6-9页

作者： jia xiaolin Liu Xinbao ZhangJihai Harbin Instiutute of Technology

Preface It is essentiae to select and decide the kindsor the quantity of additives in the production and study of plating. At present,how to evaluate theeffect of the additives is still at experimental stage,it could not truly reflect the effect of addi-lives as many contradictions and factors are mixed together. On the other hand,after a cer-taro period of using of production,every additive in the plating solution formed by the optimum prescription,will tx consumeu. The properties of the plating solution will be somewhat poorer. How to check and adjust it accurately and timely

关键词： Fast Measurement of Absorbing Performances of Additives