共查询到20条相似文献,搜索用时 15 毫秒
1.
High-performance GPS RTK software has been developed within the Geodetic Research Laboratory (GRL) at the University of New Brunswick (UNB). This software was initially designed for gantry crane auto-steering. Due to limitations with classical geodetic deformation monitoring techniques, the Canadian Centre for Geodetic Engineering (CCGE) at UNB has decided to augment its fully automated deformation monitoring system with GPS. As a result, the GRL and CCGE have combined efforts to achieve the required precision. As a first step, tests of the GPS real-time kinematic (RTK) software have been carried out at Highland Valley Copper Mine in British Columbia, Canada. An open-pit mine environment places certain constraints on the achievable accuracies attainable with GPS. Consequently, the software has been modified to meet the needs of this particular project and data have been post-processed for analysis. This paper describes the approach taken at UNB to address high precision requirements in a constrained signal availability environment. Technical and scientific aspects of the UNB software, especially in handling two predominant errors (residual tropospheric zenith delay and multipath) at the mine, are discussed. Results of tests that have been carried out at the mine are presented. 相似文献
2.
Kristine M. Larson Eric E. Small Ethan Gutmann Andria Bilich Penina Axelrad John Braun 《GPS Solutions》2008,12(3):173-177
Measurements of soil moisture are important for studies of climate and weather forecasting, flood prediction, and aquifer
recharge studies. Although soil moisture measurement networks exist, most are sparsely distributed and lack standardized instrumentation.
Measurements of soil moisture from satellites have extremely large spatial footprints (40–60 km). A methodology is described
here that uses existing networks of continuously-operating GPS receivers to measure soil moisture fluctuations. In this technique,
incoming signals are reflected off and attenuated by the ground before reception by the GPS receiver. These multipath reflections
directly affect signal-to-noise ratio (SNR) data routinely collected by GPS receivers, creating amplitude variations that
are a function of ground reflectivity and therefore soil moisture content. After describing this technique, multipath reflection
amplitudes at a GPS site in Tashkent, Uzbekistan are compared to estimates of soil moisture from the Noah land surface model.
Although the GPS multipath amplitudes and the land surface model are uncalibrated, over the 70-day period studied, they both
rise sharply following each rainfall event and slowly decrease over a period of ∼10 days. 相似文献
3.
Zhang Yongjun 《地球空间信息科学学报》2013,16(4):32-36
To obtain the GLONASS satellite position at an epoch other than reference time, the satellite's equation of motion has to be integrated with broadcasting ephemerides. The iterative detecting and repairing method of cycle slips based on triple difference residuals for combined GPS/GLONASS positioning and the iterative ambiguity resolution approach suitable for combined post processing positioning are discussed systematically. Experiments show that millimeter accuracy can be achieved in short baselines with a few hours' dual frequency or even single frequency GPS/GLONASS carrier phase observations, and the precision of dual frequency observations is distinctly higher than that of single frequency observations. 相似文献
4.
ZHANG Yongjun LIU Jingnan 《地球空间信息科学学报》2002,5(4):32-36
To obtain the GLONASS satellite position at an epoch other than reference time,the satellite‘s equation of motion has to be integrated with broadcasting ephemerides.The iterative detecting and repairing method of cycle slips based on triple difference residuals for combined GPS/GLONASS positioning and the iterative ambiguity resolution approach suitable for combined post processing positioning are discussed systematically.Experiments show that millimter accuracy can be achieved in short baselines with a few hours‘ dual frequency or even single frequency GPS/GLONASS carrier phase observation,and the precision of dual frequency observations is distinctly higher than that of single frequency observations. 相似文献
5.
Zhen Dai 《GPS Solutions》2012,16(2):267-272
A MATLAB software package for GPS cycle-slip processing is presented in this paper. It realizes cycle-slip detection and repair
in the measurement domain for GPS L1 and L2 signals. The software implements several classic approaches oriented to real-time
processing. With the graphic user interface, the user can configure the raw data, set algorithm-related parameters, add synthetic
cycle-slips, and view the detection results in both text and illustrated forms. In this paper, the theoretical background
of the cycle-slip processing is introduced first. After that, the advantages and limitations of each implemented approach
are identified. Finally, the functionalities of the software are briefly explained. 相似文献
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GPS长基线数据处理在大地测量和大型精密工程中有广泛的应用,GAMIT等国际高精度GPS数据处理软件虽能满足GPS长基线数据处理的解算精度要求,但操作复杂,且对用户的GPS理论有较高的要求。本文在分析长基线GPS数据处理中各类因素影响及误差消除方法基础上,结合图形用户界面程序设计思想,设计并实现了GPS长基线数据处理软件。经不同长度的基线数据解算结果表明,该软件可实现上千公里基线的解算,基线解算精度高,与GAMIT的解算精度相当,且解算过程自动化程度高,用户操作简单,为大范围高精度GPS数据处理提供了一种简便可行的平台。 相似文献
8.
GPS data processing with equivalent observation equations 总被引:1,自引:0,他引:1
Guochang Xu 《GPS Solutions》2002,6(1-2):28-33
A unified GPS data processing method based on equivalent observation equations is proposed. The theoretic background of this
method is given in detail. By selecting the unknowns to be eliminated as vector of zeros, i.e. the satellite clock errors,
all clock errors, the clock and ambiguity parameters or user-defined unknowns, the equivalent observation equations can be
formed. These equations are equivalent to the zero-, single-, double-, triple- or user-defined differenced equations. The
advantages of the method are that the various GPS data processing methods are unified to a unique one, whereas the observation
vector remains the original one and the weight matrix keeps the un-correlated diagonal form. Using this equivalent method
one may selectively reduce the number of unknowns without having to deal with the correlations. Several special cases of single,
double and triple difference are discussed in detail to illustrate the theory.
Electronic Publication 相似文献
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本文介绍了当前比较流行的在线GPS解算服务系统,并对其中3种有代表性的GPS在线数据处理软件(AUSPOS、SCOUT、GAPS)的解算精度进行了分析与比较,介绍了它们的原理与特点,并对它们的解算精度进行了实例分析研究。比较了它们解算结果,研究表明它们都能得到较高的精度,完全可以满足用户的要求。 相似文献
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采用GPS监测运营期大跨度桥梁时,受到交通载荷和观测噪声的影响,GPS监测序列中的振动信号(mm级)完全被湮没,如何从监测序列中提取桥梁变形信息及其振动特性是桥梁健康检测的重要内容。文中利用EMD方法对GPS监测序列进行处理,得到一定数量的本征模态函数(IMF),选取特定的IMF做信号重构和功率谱分析,得到桥梁变形信息和振动特性,相较于传统FFT方法,能准确识别结构振动频率,同时提取变形特征。 相似文献
14.
The characteristics of three GPS kinematic data processing models, Least Squares (LS), Kalman filtering and filtering are discussed and their advantages and disadvantages are compared. With observational data and pertinent data processing software, the applicable condition, context and effect of the three models are experimented. Results show that when the mobile platform is in uniform motion, the accuracy of the three models are almost equal; when the mobile platform is in stochastic acceleration, the accuracy of H∞ filtering model is superior to that of LS, while that of Kalman filtering is the worst. 相似文献
15.
Applied Research Laboratories, The University of Texas at Austin (ARL:UT) has established a cross platform open source software
project called the GPSTk or the GPS Toolkit. The GPSTk consists of a library and collection of applications that support GPS
research, analysis, and development. The code is released under the terms of the Lesser GNU Public License. The GPSTk supports
a broad range of functionality. This includes reading and writing observations in standard formats, such as RINEX, BINEX,
and SP3, ephemeris evaluation, position determination, receiver autonomous integrity monitoring (RAIM), atmospheric delay
modeling, cycle slip detection and correction, and P-code generation. The GPSTk provides the core set of functionality that
is used for GPS research and development at ARL:UT. ARL:UT has been involved with satellite navigation since Transit (the
precursor to GPS) in the 1960s and is currently conducting research in a wide variety of GPS-related fields, including precise
surveys, monitor station networks, and ionospheric studies. The GPSTk is a community-wide resource for all users of GPS and
GNSS technology. Participation is welcomed in all areas including: bug reports, new algorithms, suggestions for improvement,
and contributions of additional functionality or applications. ARL:UT continually improves the library, shepherds community
participation, and is committed to the project’s development and maintenance.
The GPS Toolbox is a column dedicated to highlighting algorithms and source code utilized by GPS Engineers and scientists.
If you have an interesting program or software package you would like to share with our readers, please pass it along; e-mail
it to us at gps-toolbox@ngs.noaa.gov. To comment on any of the source code discussed here, or to download source code, visit
our website at . This column is edited by Stephen Hilla, National Geodetic Survey, NOAA, Silver Spring, Maryland, and Mike Craymer, Geodetic
Survey Division, Natural Resources Canada, Ottawa, Ontario, Canada. 相似文献
16.
G. R. Foulger G. Beutler Roger Bilham Pall Einarsson S. Fankhauser W. Gurtner U. Hugentobler W. Jason Morgan M. Rothacher Gunnar Thorbergsson U. Wild 《Journal of Geodesy》1993,67(3):148-172
Summary The 1986 GPS survey of Iceland aimed to: (1) establish geodetic control in the South Iceland Seismic Zone (SISZ), to study destructive earthquakes there, (2) measure a country-wide network to form the basis of a new first order national network. 51 points were surveyed, with 20–30 km spacings within the SISZ and 100 km spacings elsewhere. The data were processed using the Bernese GPS software Version 3. Analysis was difficult due to poor satellite geometry and short-period ionospheric variations. However, an ambiguity-fixed, ionosphere-free solution gave accuracies of 1–2 cm in the horizontal and 2–3 cm in the vertical for the SISZ network and an ambiguity-free, ionosphere-free solution yielded accuracies of about 5 cm for the country-wide network. An ionosphere-free solution for the total survey with ambiguities fixed for the SISZ network only gave marginal additional improvements over the two separate solutions. GPS surveying has continued annually in Iceland with measurements in South Iceland in 1989 and 1992 (Hackman 1991; Sigmundsson 1992) and in North Iceland in 1987, 1990 and 1992 (Jahn et al. 1992; Foulger et al. 1992). 相似文献
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Automated GPS processing for global total electron content data 总被引:4,自引:2,他引:4
A software package known as MIT Automated Processing of GPS (MAPGPS) has been developed to automate the processing of GPS data into global total electron density (TEC) maps. The goal of the MAPGPS software is to produce reliable TEC data automatically, although not yet in real time. Observations are used from all available GPS receivers during all geomagnetic conditions where data has been successfully collected. In this paper, the architecture of the MAPGPS software is described. Particular attention is given to the algorithms used to estimate the individual receiver biases. One of the largest sources of error in estimating TEC from GPS data is the determination of these unknown receiver biases. The MAPGPS approach to solving the receiver bias problem uses three different methods: minimum scalloping, least squares, and zero-TEC. These methods are described in detail, along with their relative performance characteristics. A brief comparison of the JPL and MAPGPS receiver biases is presented, and a possible remaining error source in the receiver bias estimation is discussed. Finally, the Madrigal database, which allows Web access to the MAPGPS TEC data and maps, is described. 相似文献
19.
Divided difference filter (DDF) with quaternion-based dynamic process modeling is applied to global positioning system (GPS)
navigation. Using techniques similar to those of the unscented Kalman filter (UKF), the DDF uses divided difference approximations
of derivatives based on Stirling’s interpolation formula which results in a similar mean but different posterior covariance
compared to the extended Kalman filter (EKF) solutions. The second-order divided difference is obtained from the mean and
covariance in second-order polynomial approximation. The quaternion-based dynamic model is adopted for avoiding the singularity
problems encountered in the Euler angle method and enhancing the computational efficiency. The proposed method is applied
to GPS navigation to increase the navigation estimation accuracy at high-dynamic regions while preserving (without sacrificing)
the precision at low-dynamic regions. For the illustrated example, the second-order DDF can deliver about 41–82% accuracy
improvement as compared to the EKF. Some properties and performance are assessed and compared to those of the EKF and UKF
approaches. 相似文献
20.
A unified scheme for processing GPS dual-band phase observations 总被引:3,自引:4,他引:3
A unified computational scheme is presented for sequential least-squares processing ofGPS dual-band carrier-beat-phase observations in network-mode positioning with orbit relaxation, and in orbit determination applications.
This scheme is applicable to any spatial and temporal distribution of stations and satellites during a particularGPS experiment. Full covariance matrices can be specified for carrier-beat-phases and for weighted constraints on the ionosphere
in order to improve phase ambiguity resolution. Physically meaningful choices for these covariance matrices are developed. 相似文献