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FAIR Data and Metadata:GNSS precise positioning User Perspective

Data Intelligence 2023年第1期5卷 43-74页

作者： Ivana Ivánová Ryan Keenan Christopher Marshall Lori Mancell Eldar Rubinov Ryan Ruddick Nicholas Brown Graeme Kernich Spatial Sciences School of Earth and Planetary ScienceCurtin UniversityPerthWestern Australia6102Australia positioning Insights Carlton NorthVictoria3054Australia FrontierSI Cnr Village St and Fishplate LnDocklandsVictoria3008Australia Geoscience Australia Cnr Jerrabomberra Ave and Hindmarsh DriveSymonstonAustralian Capital Territory2609Australia

The FAIR principles of Wilkinson et al.[1]are finding their way from research into application domains,one of which is the precise positioning with global satellite navigation systems(GNSS).Current GNSS users demand that data and services are findable online,accessible via open protocols(by both,machines and humans),interoperable with their legacy systems and reusable in various *** metadata are essential in seamless communication between GNSS data and service providers and their users,and,for decades,geodetic and geospatial standards are efficiently implemented to support ***,GNSS user community is transforming from precise positioning by highly specialised use by geodetic professionals to every-day precise positioning by autonomous vehicles or wellness obsessed ***,rapid technological developments allow alternative ways of offering data and services to their *** transforming circumstances warrant a review whether metadata defined in generic geospatial and geodetic standards in use still support FAIR use of modern GNSS data and services across its novel user *** paper reports the results of current GNSS users'requirements in various application sectors on the way data,metadata and services are *** engaged with GNSS stakeholders to validate our findings and to gain understanding on their perception of the FAIR *** results confirm that offering FAIR GNSS data and services is fundamental,but for a confident use of these,there is a need to review the way metadata are offered to the *** standard compliant GNSS community metadata profile and providing relevant metadata with data on-demand,the approach outlined in this paper,is a way to manage current GNSS users'expectations and the way to improve FAIR GNSS data and service delivery for both humans and the machines.

关键词： FAIR Metadata Standards Profile precise positioning GNSS users Spatial data infrastructure

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Performance Evaluation of Low-Cost Dual-Frequency GNSS Receivers for precise positioning in Senegal: Issues and Challenges

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Journal of Analytical Sciences, Methods and Instrumentation 2024年第2期14卷 23-37页

作者： Diogoye Diouf Oustasse Abdoulaye Sall Ibrahima Khalil Gueye Fatou Ndiaye Unit de Formation et de Recherche Sciences de lIngnieur Universit Iba Der Thiam de This This Senegal

The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance and reliability, their potential use in different fields, the improvement of performance and combined systems, etc. Single-frequency GNSS receivers, which for a long time remained the only category of low-cost GNSS receivers, often limited by their level of accuracy (metric) mainly due to their single-frequency nature, have been joined in the last decade by dual-frequency GNSS receivers developed by certain manufacturers of positioning equipment. These receivers now offer possible alternatives to the relatively expensive conventional (topographic quality) or geodetic receivers and. In this study, the performance of these low-cost dual-frequency receivers was evaluated in static and real-time kinematic GNSS positioning modes. Static positioning was carried out on three points with sessions of 2 h and 4 h over three days with antenna swapping (CHC i50, Leica GS14 and Emlid Reach RS2+). Real-time observations were carried out on eleven (11) points in open, poorly open and not at all open environments, in order to assess not only performance but also receiver sensitivity in environments with a high risk of multipath. The results obtained showed an average agreement of 2 cm in planimetry between the low-cost Emlid RS2+ receiver and the Leica GS14 and CHC i50 receivers. The differences in altimetry are nevertheless greater (sometimes up to decimetres for certain points). Real-time positioning results provided an average convergence of around 1 cm on the E, N and H components with the results from the low-cost Emlid Reach RS2+ and Ublox ZED-F9P receivers and the CHC i50 receiver. Analysis of the results obtained has enabled us to highlight the various issues and challenges associated with this new generation of GNSS receivers, with a view to enhancing their appr

关键词： Low-Cost GNSS NRTK precise positioning Issues Challenges

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Functional model compensation of residual systematic errors in GNSS precise positioning

Functional model compensation of residual systematic errors ...

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第十一届中国卫星导航年会

作者： Zhetao Zhang Bofeng Li Yunzhong Shen Xiufeng He School of Earth Sciences and Engineering Hohai University College of Surveying and GeoInformatics Tongji University

Global Navigation Satellite System(GNSS)residual systematic errors have adverse impacts on precise ***,most of existing studies mainly focus on handling the part of systematic errors t

关键词： BeiDou GNSS precise positioning residual systematic error functional model compensation

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Analysis and control of micro-stepping characteristics of ultrasonic motor

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Frontiers of Mechanical Engineering 2020年第4期15卷 585-599页

作者： Ning CHEN Jieji ZHENG Xianliang JIANG Shixun FAN Dapeng FAN College of Intelligence Science and Technology National University of Defence and TechnologyChangsha 410073China

Micro-stepping motion of ultrasonic motors satisfies biomedical applications, such as cell operation and nuclear magnetic resonance, which require a precise compact-structure non-magnetization positioning device. When the pulse number is relatively small, the stopping characteristics have a non-negligible effect on the entire stepwise process. However, few studies have been conducted to show the rule of the open-loop stepwise motion, especially the shutdown stage. In this study, the modal differences of the shutdown stage are found connected with amplitude and velocity at the turn-off instant. Changes of the length in the contact area and driving zone as well as the input currents, vibration states, output torque, and axial pressure are derived by a simulation model to further explore the rules. The speed curves and vibration results in functions of different pulse numbers are compared, and the stepwise motion can be described by a two-stage two-order transfer function. A test workbench based on the Field Programmable Gate Array is built for acquiring the speed, currents, and feedback voltages of the startup–shutdown stage accurately with the help of its excellent synchronization performances. Therefore, stator vibration, rotor velocity, and terminal displacements under different pulse numbers can be compared. Moreover, the two-stage two-order model is identified on the stepwise speed curves, and the fitness over 85% between the simulation and test verifies the model availability. Finally, with the optimization of the pulse number, the motor achieves 3.3 µrad in clockwise and counterclockwise direction.

关键词： ultrasonic motor stepping characteristics pulse number control synchronous acquisition system precise positioning

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Deep-Hole Inner Diameter Measuring System Based on Non-contact Capacitance Sensor

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Transactions of Tianjin University 2010年第6期16卷 447-451页

作者：于永新张恒王宗超常以哲 School of Computer Science and Technology Tianjin University National Institute of Metrology School of Precision Instruments and Opto-Electronics Engineering Tianjin University

A precise aperture measuring system of small deep holes with capacitance sensors is presented. Based on the working principle of non-contact capacitance sensors, influence of the edge effect of gauge head is studied, and one capacitance sensor for measuring the aperture of the small blind holes or through holes is introduced. The system is composed of one positioning device, one aperture measuring capacitance sensor, one measuring circuit, and software. This system employs visual CCD and two-dimensional mic...

关键词： deep-hole measurement non-contact CCD stepping motor precise positioning

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Simulation and Design Optimization of Novel Microelectromechanical Digital-to-Analog Converter

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Journal of Semiconductors 2001年第12期22卷 1543-1545页

作者：刘清惓黄庆安东南大学微电子中心南京210096

A microelectromechanical Digital to Analog Converter (DAC) based on Weighted Gap (WG) principle is described,which is analogous to the weighed resistor DAC in electronic *** convert the input of binary voltage to the output of analog displacement,the gaps are proposed to be employed as a scale factor.A finite element method is used to simulate the performance of the *** reduce the error,the structure design is optimized and the maximum error of 0 002μm is obtained.

关键词： digital to analog converter MEMS microactuators precise positioning FEA

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On Switching Control Design for Rigid-Flexible Coupling Motion Stage

On Switching Control Design for Rigid-Flexible Coupling Moti...

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第三十九届中国控制会议

作者： Yutai Wei Ruirui Huang Hao Peng Zhijun Yang State Key Laboratory of Electronics Precision Manufacturing Technology and Equipment Guangdong University of Technology Guangdong Provincial Key Laboratory of Micro-Nano Manufacturing Technology and Equipment Guangdong University of Technology

With the development of electronics manufacturing,high-precision stage needs to meet the growing demand for performance.A novel structure,rigid-flexible coupling motion stage is featured with high control performance under different working *** the other hand,to dynamic characteristics is changeable in the process of stage motion,such that the controller is needed to accommodate *** order to give full play of the stage performance,a switch control strategy is designed in this *** judging whether the dynamic characteristics of the system have changed,switching control strategy with proportional/proportional-integral（P/PI） controllers,called segmented P/PI controllers,is carried out on the *** results indicate that,compared to the single P/PI controller,the setting time of using segmented P/PI controllers reduces drastically and the superior positioning accuracy can be maintained.

关键词： Rigid-flexible coupling motion stage precise positioning dynamic characteristics variations switching control

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A novel method corrected multipath error oriented the oceanic buoy

A novel method corrected multipath error oriented the oceani...

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第十三届中国卫星导航年会

作者： Xiangyu Tian Hongzhou Chai Institute of Surveying and Mapping Information Engineering University

The signals always form the reflection over the sea. The characteristics and correct method of the multipath over the sea are worthy of research. Based on the assumption that the high-precision posterior residual only contains multipath error and noise, this paper adopts forward and backward filtering estimation and PPP-AR strategy to obtain the high-precision observational post-residual and then calculates the multipath error effect based on the mean denoising method. The azimuth and elevation angle mapping relationship of the azimuth angle and elevation angle are constructed, the station center multipath hemispherical map（MHM） is constructed, and the different grid resolutions of MHM are experimentally studied. The experimental results show that the MHM model can effectively improve the positioning effect of the marine buoy rather than no multipath correction. Not only the positioning accuracy can be improved, but the ambiguity fixed-rate and convergence time of positioning can also be improved, especially the 2°×2° resolution of the MHM model has good results in both static and dynamic scenarios.

关键词： BDS oceanic buoy multipath precise positioning

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ClinicalexperiencewiththecordiscoronarystentintheChinesepopulation

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Chinese Medical Journal 1998年第4期111卷 70-70页

作者： K. Fan W.H. Chow L. Chow A. Yip K.L. Cheung University Cardiac Medical Unit Grantham Hospital 125 Wong Chuk Hang Road Aberdeen Hong Kong

Objective To assess the safety and efficacy of the new Cordis coronary stent in the Chinese *** A total of 32 patients recieved 34 Cordis stents (target lesions of 32) from July to December 1995 in our hospital. Vessel distribution was 18 LAD (53%), 8 Lcx (23.5%) and 8 RCA (23.5%).Methods All cases were studies retrospectively. The coronary lesions were predilated with standard balloon angioplasty followed by implantation of Cordis stents. The reference diameter of the vessels and the minimal luminal diameters (both before and after stent implantation) were measured by quantitative angiography. All patients were followed up at mean peroid of 3 months with regards to their symptoms and angiographic follow-up at 6 month's time were carried out in 8 *** Delivery success was achieved in all lesions except 1 unsuccessful delivery due to failure to negotiate an acute angle of a left main vessel to LAD. Average MLD post stenting was satisfactory (0.53±0.36 mm vs 3.32±0.34 mm) compared to reference diameter of 3.13±0.4 mm. There was 1 patient with complication of subacute stent thrombosis. Another patient died 5 weeks later from non-ischaemic end stage heart failure secondary to severe aortic regurgitation. Loop seperations occurred in 2 stents (5.8%) during *** The Cordis stent implantation is efficacious with high angiographic success rate. The strong radiopacity facilitates precise positioning of the stent in the target lesions. Our experience in the Chinese population is favourable. Stent deformity was possible. For smaller stents of 3 mm, higher pressure of balloon inflation for deployment followed by adequate anticoagulation is recommended. Further studies are required to investigate the long term restenosis rate.

关键词： Chinese population stent implantation aortic regurgitation precise positioning balloon angioplasty coronary stent heart failure

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