Journal of Global Positioning Systems最新文献_第5页

Three Carrier Ambiguity Resolutions: Generalised Problems, Models and Solutions 三种载波歧义解决:一般化的问题、模型和解决方案

Journal of Global Positioning Systems Pub Date : 2009-12-01 DOI: 10.5081/jgps.8.2.115

Yanming Feng, Bofeng Li

{"title":"Three Carrier Ambiguity Resolutions: Generalised Problems, Models and Solutions","authors":"Yanming Feng, Bofeng Li","doi":"10.5081/jgps.8.2.115","DOIUrl":"https://doi.org/10.5081/jgps.8.2.115","url":null,"abstract":"In this paper, the problems of three carrier phase ambiguity resolution (TCAR) and position estimation (PE) are generalized as real time GNSS data processing problems for a continuously observing network on large scale. In order to describe these problems, a general linear equation system is presented to uniform various geometry-free, geometry-based and geometry-constrained TCAR models, along with state transition questions between observation times. With this general formulation, generalized TCAR solutions are given to cover different real time GNSS data processing scenarios, and various simplified integer solutions, such as geometry-free rounding and geometry-based LAMBDA solutions with single and multiple-epoch measurements. In fact, various ambiguity resolution (AR) solutions differ in the floating ambiguity estimation and integer ambiguity search processes, but their theoretical equivalence remains under the same observational systems models and statistical assumptions. TCAR performance benefits as outlined from the data analyses in some recent literatures are reviewed, showing profound implications for the future GNSS development from both technology and application perspectives.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132513927","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}

引用次数: 12

Differences in Accuracies and Fitting Surface Planes of Two Error Models for NRTK in GPSnet GPSnet中NRTK两种误差模型的精度及拟合面差

Journal of Global Positioning Systems Pub Date : 2009-12-01 DOI: 10.5081/JGPS.8.2.154

Suqin Wu, Kefei Zhang, D. Silcock

引用次数: 6

Analysis of Ionospheric Range Delay Corrections for Navigation in South American Low-Latitude Regions 南美低纬度地区导航电离层距离延迟校正分析

Journal of Global Positioning Systems Pub Date : 2009-12-01 DOI: 10.5081/JGPS.8.2.164

A. Meza, L. Fernández

引用次数: 0

Application of Mixed-radix FFT Algorithms in Multi-band GNSS Signal Acquisition Engines 混合基数FFT算法在多波段GNSS信号采集引擎中的应用

Journal of Global Positioning Systems Pub Date : 2009-12-01 DOI: 10.5081/JGPS.8.2.174

N. Shivaramaiah, A. Dempster, C. Rizos

{"title":"Application of Mixed-radix FFT Algorithms in Multi-band GNSS Signal Acquisition Engines","authors":"N. Shivaramaiah, A. Dempster, C. Rizos","doi":"10.5081/JGPS.8.2.174","DOIUrl":"https://doi.org/10.5081/JGPS.8.2.174","url":null,"abstract":"Due to their fast operation, Fast Fourier Transform (FFT)-based coarse signal synchronization methods are an attractive option for Global Navigation Satellite System (GNSS) receiver baseband signal processing. However, there are several reasons why the utility of FFT-based methods is dependent on understanding the trade-off between synchronization speed and the required processing power. Firstly, the new signals of the GNSS family, for instance Galileo and GPS modernization, employ longer period Pseudo Random Noise (PRN) codes and higher signal bandwidths, which demand FFTs of large transform lengths. Secondly, to gain an advantage in positioning performance, next generation receivers target multiple GNSS signals, and since each signal has its own code length (and hence a minimum sampling frequency), the receiver should accommodate FFT blocks of varying lengths. This paper discusses the requirements of FFT-based algorithms for such a multiband receiver and analyzes the application of primefactor and mixed-radix FFT algorithms. A novel way of factorizing different transform lengths into smaller transforms and then combining these smaller-point FFTs to compute the larger required FFTs is described. It is shown that the use of the proposed architecture reduces the computational load (or processor cycles) and increases the re-usability of the acquisition search engine to process different signals.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129046886","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}

引用次数: 7

Performance Evaluation of Combined L1/L5 Kalman Filter-Based Tracking versus Standalone L1/L5 Tracking in Challenging Environments 挑战性环境下基于L1/L5卡尔曼滤波的联合跟踪与独立L1/L5跟踪的性能评估

Journal of Global Positioning Systems Pub Date : 2009-09-25 DOI: 10.5081/JGPS.8.2.135

D. Salem, C. O'Driscoll, G. Lachapelle

{"title":"Performance Evaluation of Combined L1/L5 Kalman Filter-Based Tracking versus Standalone L1/L5 Tracking in Challenging Environments","authors":"D. Salem, C. O'Driscoll, G. Lachapelle","doi":"10.5081/JGPS.8.2.135","DOIUrl":"https://doi.org/10.5081/JGPS.8.2.135","url":null,"abstract":"The ever-increasing demand on GPS to perform in challenging environments is the main motivation behind this research. With the existence of these challenging environments, more research is directed towards enhancing the tracking capabilities. Several solutions have been proposed to enable high sensitivity tracking using only one signal. However, new GPS signals are now available, in addition to the conventional L1 signal. Being transmitted from the same space vehicle through the same environment, the errors between these signals are correlated. Hence, an increase in tracking sensitivity can be achieved by combining two or more of these signals. This paper proposes the idea of combining the L1 and L5 signals using one Kalman filter, where the correlator outputs of the two signals are used to estimate the tracking errors. The performance of this combined Kalman filter is compared to a similar Kalman filter that is used separately for tracking each of the two signals. The performance of both filters is compared in environments suffering urban canyon multipath, moderate ionospheric errors, in addition to a motion model of a typical vehicle. The combined Kalman filter is shown to outperform the separate Kalman filter, both in the tracking errors and in the filter statistics.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122873602","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}

引用次数: 7

A Complexity Reduced Frequency Domain Receiver for Galileo and GPS L1 Signals 一种用于伽利略和GPS L1信号的低复杂度频域接收机

Journal of Global Positioning Systems Pub Date : 2009-09-25 DOI: 10.5081/JGPS.8.2.124

Feng Xu, Yang Gao

{"title":"A Complexity Reduced Frequency Domain Receiver for Galileo and GPS L1 Signals","authors":"Feng Xu, Yang Gao","doi":"10.5081/JGPS.8.2.124","DOIUrl":"https://doi.org/10.5081/JGPS.8.2.124","url":null,"abstract":"The L1/E1 band will soon be populated with four different signals, namely the GPS C/A, L1C, Galileo E1B, E1C codes. The frequency domain receiver, which can provide parallel correlation and process all the signals in a common structure, becomes a promising solution for multi-code and multi-modulation processing. However, the conventional frequency domain receivers have high computational loads to perform the FFT/IFFT operations, especially when the receivers operate at a high sampling rate. To reduce the computational loads of the frequency domain receiver, a new correlation method with signal down sampling in the frequency domain is proposed. The down sampling is achieved by pruning the high frequency parts of the signal spectrum and then performing IFFT in smaller sizes. In addition, a novel open loop code delay estimation method without correlation interpolation is proposed. The method first obtains the integer parts of the code delay by the correlation peak detection, then gets the residual errors by code delay discrimination and finally obtains the precise estimation by post filtering. The results indicate that this new method not only reduces the complexity, but also improves the tracking sensitivity comparing to the conventional closed tracking loops.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128502208","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}

引用次数: 2

Evaluation of EPOS-RT for Real-time Deformation Monitoring EPOS-RT用于实时变形监测的评价

Journal of Global Positioning Systems Pub Date : 2009-06-30 DOI: 10.5081/JGPS.8.1.1

Junping Chen, M. Ge, J. Douša, G. Gendt

引用次数: 10

GNSS networks in algebraic graph theory, Journal of Global Positioning Systems 代数图论中的GNSS网络，全球定位系统学报

Journal of Global Positioning Systems Pub Date : 2009-06-30 DOI: 10.5081/JGPS.8.1.53

A. Lannes, S. Gratton

{"title":"GNSS networks in algebraic graph theory, Journal of Global Positioning Systems","authors":"A. Lannes, S. Gratton","doi":"10.5081/JGPS.8.1.53","DOIUrl":"https://doi.org/10.5081/JGPS.8.1.53","url":null,"abstract":"A new approach to the GNSS network is presented. Here, this approach is restricted to the case where the user handles the network data for his own objectives: the satellite-clock biases are not estimated. To deal with the general case where some data are missing, the corresponding theoretical framework appeals to some elementary notions of algebraic graph theory. As clarified in the paper, the notion of closure delay (CD) then generalizes that of double difference (DD). The body of the paper is devoted to the implications of this apporach in GNSS data processing. One is then led to define local variables, which depend on the successive epochs of the time series, and a global variable which remains the same all over these epochs, with however possible state transitions from time to time. In the period defined by two successive transitions, the problem to be solved in the least-square sense is governed by a linear equation in which the key matrix has an angular block structure. This structure is well suited to recursive QR factorization. The state transitions included by the variations of the GNSS graph are then handled in an optimal manner. Solving the integer-ambiguity problem via LLL decorrelation techniques is also made easier. At last but not the least, is centralized mode, this approach particularly well suited to quality control.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"43 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":"115665126","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}

引用次数: 12

Details of an Imaging System Based on Reflected GPS Signals and Utilizing SAR Techniques 基于反射GPS信号并利用SAR技术的成像系统细节

Journal of Global Positioning Systems Pub Date : 2009-06-30 DOI: 10.5081/JGPS.8.1.87

M. Usman, D. Armitage

引用次数: 4

Horizontal strain rate distribution on an active ice shelf rift from in-situ GPS data 基于GPS的活动冰架裂谷水平应变率分布

Journal of Global Positioning Systems Pub Date : 2009-06-30 DOI: 10.5081/JGPS.8.1.6

V. Janssen

{"title":"Horizontal strain rate distribution on an active ice shelf rift from in-situ GPS data","authors":"V. Janssen","doi":"10.5081/JGPS.8.1.6","DOIUrl":"https://doi.org/10.5081/JGPS.8.1.6","url":null,"abstract":"Mass loss from the Antarctic ice sheet predominantly occurs at the fringing ice shelves via iceberg calving, which is controlled by the initiation and propagation of large rifts that precede iceberg detachment and can lead to ice shelf break-up. This paper reports on the analysis of Global Positioning System (GPS) data collected at an active rift system on the Amery Ice Shelf, East Antarctica, over two field seasons. Horizontal strain rates are determined for a network of 11 sites observed over three weeks during the 2004/05 Antarctic summer period, and the results are combined with, and compared to, strain rates obtained in the 2002/03 season. Maximum principal strain rates across the network vary between 6 and 32 [x 10-3/yr], while minimum principal strain rates are generally about 1-17 [x 10-3/yr]. Changes evident in the strain distribution can mostly be attributed to existing fractures passing through the GPS network and the episodic movement of the rift tip. It is confirmed that rift propagation in 2005/06 was slowing down. Opening rates are inferred from baselines situated normal to the rift. Analysis of the network using a cumulative sum approach is found to be an effective method to detect small baseline length changes associated with rift propagation.","PeriodicalId":237555,"journal":{"name":"Journal of Global Positioning Systems","volume":"31 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":"127673112","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}

引用次数: 3