Journal of Global Positioning Systems最新文献

{"title":"Detecting Multiple failures in GPS/INS integrated system: A Novel architecture for Integrity Monitoring","authors":"U. I. Bhatti, W. Ochieng","doi":"10.5081/JGPS.8.1.26","DOIUrl":"https://doi.org/10.5081/JGPS.8.1.26","url":null,"abstract":"GPS is a widely used satellite navigation system. By design, there is no provision for real time integrity information within the Standard Positioning Service (SPS) which is available to the civilian community. However, in safety critical sectors like aviation, stringent integrity performance requirements must be met. This can be achieved using the GIC (GPS Integrity Channel) or RAIM (Receiver Autonomous Integrity Monitoring) or both. RAIM, the most cost effective method relies on data consistency, and therefore requires redundant measurements for its operation. An external aid to provide this redundancy can be in the form of an Inertial Navigation system (INS). This should enable continued performance even during RAIM holes. RAIM algorithms have traditionally been designed for the situation when only one failure occurs at a time. However, due to tighter alert limits and usage of GPS in urban environments there is now a focus on extending the RAIM concept to include multiple failures. Furthermore, in aviation, detection of simultaneous multiple slowly growing errors (SGE) is very challenging particularly in the case of integrated GPS/INS systems. This paper provides a detailed survey of RAIM approaches used to detect multiple failures proposed by navigation and geodesy communities. Furthermore the paper extends a previous algorithm proposed by the authors for the detection of a single SGE to the simultaneous multiple failure case for stand-alone GPS and integrated GPS/INS systems. Simulated and real data results attest to the effectiveness of the approach proposed. The developed algorithm is successful in the detection of multiple failures in GPS as well as in the INS. Furthermore isolation of the faulty sensor (GPS or INS) is possible with the same parallel filter structure. Hence, this approach will enhance the integrity of a GPS/INS integrated system installed on an aircraft.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122295003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simplified Algorithms of Variance Component Estimation for Static and Kinematic GPS Single Point Positioning","authors":"J. Wang, N. Gopaul, B. Scherzinger","doi":"10.5081/JGPS.8.1.43","DOIUrl":"https://doi.org/10.5081/JGPS.8.1.43","url":null,"abstract":"This paper adapts Helmert’s simplified variance component estimation (VCE) algorithm for static and kinematic GPS single point positioning (SPP). First, the VCE algorithm for a static GPS SPP is formulated. Second, the concept of redundancy contribution of observations is developed in Kalman filtering so that the VCE algorithm is further delivered in Kalman filtering. The proposed VCE approach in Kalman filtering allows the variance components for individual measurement noises and individual independent process noises to be estimated. Some VCE numerical results from static and kinematic GPS datasets are presented and discussed.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"74 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116325458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliability Analysis in Kalman Filteirng","authors":"J. Wang","doi":"10.5081/JGPS.8.1.101","DOIUrl":"https://doi.org/10.5081/JGPS.8.1.101","url":null,"abstract":"This manuscript centers on the reliability theory and its applications in Kalman filtering. Especially, it delivers a distinct derivation of the redundancy contribution - the key element of reliability theory for the Kalman filter algorithm that has not been comprehensively discussed in literature at present. A distinction is made between the system innovation vector and the measurement (or pseudo measurement) residual vector. This allows to directly analyse the observation vector and the process noise vector. Particular attention is paid not only to the theoretical fundamentals of the reliability, and also to the","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130872652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extended GNSS Ambiguity Resolution Models with Regularization Criterion and Constraints","authors":"Bofeng Li","doi":"10.5081/jgps.8.2.148","DOIUrl":"https://doi.org/10.5081/jgps.8.2.148","url":null,"abstract":"This paper firstly presents an extended ambiguity resolution model that deals with an ill-posed problem and constraints among the estimated parameters. In the extended model, the regularization criterion is used instead of the traditional least squares in order to estimate the float ambiguities better. The existing models can be derived from the general model. Secondly, the paper examines the existing ambiguity searching methods from four aspects: exclusion of nuisance integer candidates based on the available integer constraints; integer rounding; integer bootstrapping and integer least squares estimations. Finally, this paper systematically addresses the similarities and differences between the generalized TCAR and decorrelation methods from both theoretical and practical aspects.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129002677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Requirements for the Next Generation Standardized Location Technology Protocol for Location-Based Services","authors":"L. Wirola, Ismo Halivaara, J. Syrjärinne","doi":"10.5081/JGPS.7.2.91","DOIUrl":"https://doi.org/10.5081/JGPS.7.2.91","url":null,"abstract":"The booming location-based services business requires more accuracy and availability from positioning technologies. While several proprietary location and positioning protocols have been developing in the market, scalable and cost-effective solutions can only be realized using standardized solutions. Currently the positioning protocol standardization is concentrated in the 3GPP and 3GPP2 that define Control Plane (CP) positioning technologies for Radio Access Networks’ native use. The limitations of the control plane in terms of architecture and bearer protocols are necessarily reflected in the CP positioning protocols and limit the feature sets offered. In addition to 3GPP/2 positioning technologies are also defined in WiMAX Forum and in IEEE for WLAN networks. Location protocols in IP-networks, such as OMA SUPL (Open Mobile Alliance Secure User Plane Location protocol), encapsulate the CP positioning protocols. Thus the limitations of the CP protocols have also been copied to the User Plane, although the bearer there would be much more capable. Due to the shortcomings in the CP positioning protocols, standardization activity for a new bearer-independent positioning protocol is proposed in order to fulfil the needs of the future location-based services. This paper discusses the current solutions, trends in the location technologies and outlines requirements for the future location technology protocol in terms of protocol features and data content. The development of a generic positioning technology protocol is seen as an important development towards a convergence in the location protocols and the capability to provide location-based services irrespective of the bearer network. This has a major impact on the service development as well as user experience.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132388173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calibration and Stochastic Modelling of Inertial Navigation Sensor Erros","authors":"M. El-Diasty, S. Pagiatakis","doi":"10.5081/JGPS.7.2.170","DOIUrl":"https://doi.org/10.5081/JGPS.7.2.170","url":null,"abstract":"The integration of Global Positioning System (GPS) with an inertial measurement unit (IMU) has been widely used in many applications of positioning and orientation. The performance of a GPS-aided inertial integrated navigation system is mainly characterized by the ability of the IMU to bridge GPS outages. This basically depends on the inertial sensor errors that cause a rapid degradation in the integrated navigation solution during periods of GPS outages. The inertial sensor errors comprise systematic and random components. In general, systematic errors (deterministic) can be estimated by calibration and therefore they can be removed from the raw observations. Random errors can be studied by linear or high order nonlinear stochastic processes. These stochastic models can be utilized by a navigation filter such as, Kalman filter, to provide optimized estimation of navigation parameters. Traditionally, random constant (RC), random walk (RW), Gauss-Markov (GM), and autoregressive (AR) processes have been used to develop the stochastic model in the navigation filters. In this technical note, the inertial sensor errors are introduced and discussed. Subsequently, a six-position laboratory calibration test is described. Then, mathematical models for RC, RW, GM, and AR stochastic models with associated variances for gyros and accelerometer random errors are presented along with a discussion regarding ongoing research in this field. Also, the implementation of a stochastic model in a loosely coupled INS/GPS navigation filter is explained.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"31 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123208943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Miami Redblade III: A GPS-aided Autonomous Lawnmower","authors":"G. Newstadt, K. Green, D. Anderson, M. Lang, Y. Morton, J. McCollum","doi":"10.5081/JGPS.7.2.115","DOIUrl":"https://doi.org/10.5081/JGPS.7.2.115","url":null,"abstract":"This paper describes the technical aspects of the Redblade III, Miami University's third generation autonomous lawnmower. The Redblade III was created for entrance in the Institute of Navigation's 4th Annual Autonomous Lawnmower Competition by a team of undergraduate students majoring in electrical, computer, and mechanical engineering at Miami University. This paper details the five major subsystems of the lawnmower, including (1) the sensing system, (2) the control system, (3) the mechanical chassis system, (4) the safety system, and (5) the base monitoring and testing system. The paper discusses each aforementioned system in detail, along with providing cost analysis and conclusions.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"475 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131988568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Architecture and Benefits of an Advanced GNSS Software Receiver","authors":"M. Petovello, C. O'Driscoll, G. Lachapelle, D. Borio, Hasan Murtaza","doi":"10.5081/JGPS.7.2.156","DOIUrl":"https://doi.org/10.5081/JGPS.7.2.156","url":null,"abstract":"This paper describes a GNSS software receiver architecture and the associated benefits in terms of algorithm flexibility and processing efficiency. For the latter, different signal processing algorithms and implementations are considered including processing with a Graphics Processing Unit (GPU); a novel implementation in the GNSS community. The massively parallel processing capability of the GPU is demonstrated relative to other processing optimizations. Sample results of GPS processing are presented including centimetre level positioning. Results obtained with some of the Galileo and GLONASS signals are also included to demonstrate the flexibility of the receiver.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123408965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Conceptual Framework for Server-Based GNSS Operations","authors":"Samsung Lim, C. Rizos","doi":"10.5081/JGPS.7.2.125","DOIUrl":"https://doi.org/10.5081/JGPS.7.2.125","url":null,"abstract":"The diversification of Global Navigation Satellite Systems (e.g. the current and modernized GPS, the revitalized GLONASS, the planned Galileo and Compass), is an opportunity for engineers, surveyors and geodesists because of expected improvements in positioning accuracy, operational flexibility, redundancy, and quality assurance. Recent research activities include new algorithms for multiple frequency ambiguity resolution, software-based receivers for reconfigurability, network-wide corrections for utilising redundancy, reversed real-time kinematic schemes for quality/accuracy improvement, and a wide range of rover-side applications. This paper discusses the integration of these “pieces” of work into a new framework and facilitates information and communication technologies in order to derive benefits from network infrastructure such as continuously operating reference stations and local/regional GPS networks. Operational models are proposed for precise point positioning and real-time kinematic services including “near real-time” applications, which require an optimal design to balance the computational overhead with data communication latency. The proposed framework is designed to be a comprehensive, serverbased, and thin-client platform. It provides end-users with “out-of-the-box” services. End-users should be able to obtain extensive GNSS capabilities and high productivity without conventional constraints such as an expensive set of receivers, proprietary data formats, user-installed carrier phase processing software, incomplete interoperability, limited communication links, etc. The framework also adopts up-to-date database technologies and web technologies that enable servers to perform data management and spatial analysis, while end-users are able to syndicate data and create their own business models. The framework has been applied to Sydney Network (SydNET), a network of continuously operating reference stations located in Sydney, Australia. It is expected that the new framework will be versatile enough to cope with a diverse range of user performance requirements and the operational requirements for communications and positioning computations.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133395685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Running Average Function to Non-Dispersive Errors of Network-Based Real-Time Kinematic Positioning","authors":"Samsung Lim, C. Rizos, T. Musa","doi":"10.5081/JGPS.7.2.148","DOIUrl":"https://doi.org/10.5081/JGPS.7.2.148","url":null,"abstract":"The GPS errors can be separated into a frequencydependent or dispersive component (e.g. the ionospheric delay) and a non-dispersive component (e.g. the tropospheric delay and orbit biases). Dispersive and nondispersive errors have different dynamic effects on the GPS network corrections. The former exhibits rapid changes with high variations due to the effect of free electrons in the ionosphere, whilst the latter change slowly and smoothly over time due to the characteristic behaviour of the tropospheric delay and the nature of orbit biases. It is found that the non-dispersive correction can be used to obtain better ionosphere-free measurements, and therefore helpful in resolving the long-range integer ambiguity of the GPS carrier-phase measurements. A running average is proposed in this paper to provide a stable network correction for the nondispersive term. Once the integer ambiguities have been resolved, both dispersive and non-dispersive corrections can be applied to the fixed carrier-phase measurements for positioning step so as to improve the accuracy of the estimated coordinates. Instantaneous positioning i.e. single-epoch positioning, has been tested for two regional networks: SydNET, Sydney, and SIMRSN, Singapore. The test results have shown that the proposed strategy performs well in generating the network corrections, fixing ambiguities and computing a user’s position.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129379645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}