Journal ArticleDOI
GPS signal diffraction modelling: the stochastic SIGMA-δ model
TLDR
The SIGMA-Δ model has been developed for stochastic modelling of global positioning system (GPS) signal diffraction errors in high precision GPS surveys as mentioned in this paper, where the basic information used in the SIGMA Δ model is the measured carrier-to-noise power-density ratio (C/N0).Abstract:
The SIGMA-Δ model has been developed for stochastic modelling of global positioning system (GPS) signal diffraction errors in high precision GPS surveys. The basic information used in the SIGMA-Δ model is the measured carrier-to-noise power-density ratio (C/N0). Using the C/N0 data and a template technique, the proper variances are derived for all phase observations. Thus the quality of the measured phase is automatically assessed and if phase observations are suspected to be contaminated by diffraction effects they are weighted down in the least-squares adjustment. The ability of the SIGMA-Δ model to reduce signal diffraction effects is demonstrated on two static GPS surveys as well as on a kinematic high-precision GPS railway survey. In cases of severe signal diffraction the accuracy of the GPS positions is improved by more than 50% compared to standard GPS processing techniques.read more
Citations
More filters
Journal ArticleDOI
Least-squares variance component estimation
TL;DR: In this paper, the LS-VCE method is described for three classes of weight matrices: a general weight matrix, a weight matrix derived from the class of elliptically contoured distributions.
Journal ArticleDOI
Instantaneous geodetic positioning at medium distances with the Global Positioning System
TL;DR: In this paper, a new method of Global Positioning System (GPS) data analysis, called instantaneous positioning, at spatial scale lengths typical of interstation spacings in a modern crustal motion network was proposed.
Journal ArticleDOI
Stochastic assessment of GPS carrier phase measurements for precise static relative positioning
TL;DR: A stochastic assessment procedure has been developed to take into account the heteroscedastic, space- and time-correlated error structure of the GPS measurements, and results indicate that the reliability of the estimated positioning results is improved and the quality of ambiguity resolution can be more realistically evaluated.
Journal ArticleDOI
An extended weight model for GPS phase observations
TL;DR: In this article, an extended weight model using robust estimation is presented, in particular the Danish Method, which combines the information inherent in C/N0 and the residuals of the double differenced phase observations in order to model random errors and signal distortion effects.
Journal ArticleDOI
Sidereal filtering based on single differences for mitigating GPS multipath effects on short baselines
TL;DR: Wavelet spectra have shown that the proposed sidereal filtering algorithm is more effective in mitigating multipath errors of both long and short periods and is applicable when different GPS satellites are observed on different days.
References
More filters
Journal ArticleDOI
Variances of GPS Phase Observations: The SIGMA-ɛ Model
H. Hartinger,F. K. Brunner +1 more
TL;DR: The proposed SIGMA-ɛ model allows the use of noisier phase data from very low elevation satellites to overcome poor satellite geometry problems and to yield higher accuracies for GPS surveys than the using of the standard weighting scheme.
Numerical Modelling of GPS Signal Propagation
Rodney A. Walker,Kurt Kubik +1 more
TL;DR: In this article, the effects of diffraction and multipath on the propagation of GPS signals over arbitrary terrain surfaces were modelled accurately for GPS propagation over any type of terrain using a digital terrain model.
Book ChapterDOI
Signal distortion in high precision gps surveys
H. Hartinger,F.K. Brunner +1 more
TL;DR: It is shown that GPS signal distortions can significantly influence the accuracy of the results of a GPS survey and it is proved that this effect is hardware and software independent.