The Ionosphere-weighted GPS baseline precision in canonical form   总被引：2，自引：2，他引：0  

P. J. G. Teunissen 《Journal of Geodesy》1998,72(2):107-111

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Weighting GPS Dual Frequency Observations: Bearing the Cross of Cross-Correlation   总被引：5，自引：0，他引：5  

Peter J. G. Teunissen  N. F. Jonkman  C. C. J. M. Tiberius 《GPS Solutions》1998,2(2):28-37

A proper choice of the observation weight matrix is of importance for both adjusting and testing GPS data. Our understanding of the noise characteristic of GPS observations, on which the weight matrix should be based, is, however, still underdeveloped. This makes it difficult to draw up an appropriate weight matrix. The first and foremost purpose of this contribution is therefore to draw attention to the need to improve upon our rudimentary knowledge of the GPS stochastic model. To this end, results will be presented of a relatively simple case study in which the possible presence of cross-correlation between observables is considered. With these results we hope to spur further discussion and research on this important topic. ? 1998 John Wiley & Sons, Inc.  相似文献   

一个新的GNSS模糊度估计类   总被引：2，自引：0，他引：2  

P.J.G.Teunissen 《武汉大学学报(信息科学版)》2004,29(9):757-762

介绍了一类新的GNSS模糊度估计。因为该类遵循移去一恢复原理，称之为整数等变估计类。本文将说明整数等变估计类较整数估计类和线性无偏估计类的范围要大，同时给出一个相当有用的整数等变估计类的表达式。这个表达式揭示了整数等变估计类的结构，并显示该表达式如何在浮点解的基础上实现整数等变估计。最后还提出最优整数估计。  相似文献   

The parameter distributions of the integer GPS model   总被引：6，自引：0，他引：6  

P. J. G. Teunissen 《Journal of Geodesy》2002,76(1):41-48

 A parameter estimation theory is incomplete if no rigorous measures are available for describing the uncertainty of the parameter estimators. Since the classical theory of linear estimation does not apply to the integer GPS model, rigorous probabilistic statements cannot be made with reference to the classical results. The fact that integer parameters are involved in the estimation process forces a reappraisal of the propagation of uncertainty. It is with this purpose in mind that the joint and marginal distributional properties of both the integer and non-integer parameters of the GPS model are determined. These joint distributions can also be used to determine the distribution of functions of the parameters. As an important example, the distribution of the vector of ambiguity residuals is determined. Received: 30 January 2001 / Accepted: 31 July 2001  相似文献   

Structure of mean winds and turbulence in the planetary boundary layer over rural terrain   总被引：3，自引：1，他引：3  

H. W. Teunissen 《Boundary-Layer Meteorology》1980,19(2):187-221

A detailed analysis has been carried out of the temporal and spatial structure of mean winds and turbulence in the neutrally-stable planetary boundary layer over typically rural terrain. The data were obtained from a horizontal array of tower-mounted propeller anemometers (z = 11 m) during a five-hour period for which the mean wind direction was virtually perpendicular to the main span of the array. Various turbulence characteristics have been obtained for all three components of velocity and have been compared with idealized models for such a flow and with some of the other available atmospheric results.Considerable tower-to-tower and block-to-block variability has been observed in many of the measured results, particularly in those for the horizontal-component integral scales. Surface shear stress, roughness length and turbulence intensities were in good agreement with expected values for such a site. Power spectra for all components displayed significantly more energy at middle and lower frequencies than that observed by Kaimal et al. (1972) over flat, relatively featureless terrain. This is felt to be a result of the generally rougher gross features of the terrain in the present case and has led to the development of a modified version of the Kaimal-spectral model which fits the observed data better than either the original Kaimal model or the von Kármán model. It is suggested that it may in future be possible to represent power spectra over a wide range of terrain types by using such a modified spectral model.Integral scales of turbulence were calculated by three different techniques and in most cases displayed a strong dependence on the technique used. Averaged values of scale showed reasonable agreement with most of the available atmospheric data and with the values suggested by ESDU (1975). The anticipated elongation of turbulent eddies in the longitudinal direction was confirmed for all three velocity components, although it was found to be not as large as some other observations.  相似文献   

Minimal detectable biases of GPS data   总被引：4，自引：1，他引：3  

P. J. G. Teunissen 《Journal of Geodesy》1998,72(4):236-244

In this contribution closed-form expressions are given for the minimal detectable biases of single- and dual-frequency pseudo-range and carrier-phase data. They are given for three different single-baseline models. These are the geometry-free model and two variants of the geometry-based model, namely the roving and stationary variants. The baselines are considered to be sufficiently short such that orbital uncertainties in the fixed orbits and residual ionospheric and tropospheric delays can be assumed absent. The stochastic model used is one that permits cross-correlation and the use of different variances for individual GPS observables, including the possibility to weigh the observables in dependence on which satellite is tracked. Received: 23 April 1997 / Accepted: 27 October 1997  相似文献   

IRNSS/NavIC Single-Point Positioning: A Service Area Precision Analysis     

Safoora Zaminpardaz  Peter J. G. Teunissen  Nandakumaran Nadarajah 《Marine Geodesy》2017,40(4):259-274

The Indian Regional Navigation Satellite System (IRNSS) has recently (as of May 2016) become operational. The system has been developed with the objective of offering positioning, navigation, and timing (PNT) to users in its two service areas, covering the Indian landmass and the Indian Ocean, respectively. It is the goal of this contribution to provide further insight into the full-constellation L5 pseudorange single-point positioning (SPP) capabilities of the system. A detailed dilution of precision (DOP) analysis of its two service areas, including the identification, in location and time, of poor receiver-satellite geometries is provided. It is hereby demonstrated how the impact of some of these poor receiver-satellite geometries can be mitigated by means of height-constraining. An overview and analysis of the SPP precision is also provided including easy-to-use representative day-averaged values for a grid of locations covering the two service areas.  相似文献   

A canonical theory for short GPS baselines. Part I: The baseline precision   总被引：5，自引：4，他引：1  

P. J. G. Teunissen 《Journal of Geodesy》1997,71(6):320-336

The present contribution is the first of four parts. It considers the precision of the floated and the fixed baseline. A measure is introduced for the gain in baseline precision which is experienced when the carrier phase double-differenced ambiguities are treated as integers instead of as reals. The properties of this measure are analyzed, and it is shown by means of principal angles how it relates to the change over time of the relative receiver-satellite geometry. We also present canonical forms of the baseline variance matrices for different measurement scenarios. These canonical forms make the relation between the various variance matrices transparent and thus present a simple way of studying their relative merits. Received: 16 July 1996; Accepted: 14 November 1996  相似文献