Impact of GPS satellite sky distribution.
|Abstract:||This research is a study of the impact of the Global Positioning System (GPS) satellite sky distribution on the propagation of some important errors in precise static relative positioning. Even the full GPS constellation of 24 satellites will not provide a uniform distribution of the visible satellites in the observer's sky. The satellite sky distribution is a function of site latitude, because GPS stellite orbits have inclinations different than 90°. Covariance matrix behaviour and the effects of some important systematic errors on precise relative positioning are studied as a function of GPS satellite sky distribution, using an improved simulation technique originally suggested by Geiger of ETH Zürich. Unknowns considered are the station coordinates, the relative receiver clock parameter and the relative tropospheric zenith delay parameter. Biases analysed are: relative tropospheric refraction, absolute ionospheric refraction, offset in the horizontal coordinates of the fixed station and offset in the height of the fixed station. Orientation and shape of the confidence ellipsoid, and correlation among the selected unknowns, are used to monitor the behaviour of the covariance matrix. Systematic errors introduced in the station network by the biases are represented as station coordinate discrepancies and affine transformation parameters. Numerical values of these parameters are presented for satellite configurations produced by both the protogype and the full GPS constellations. The magnitudes of the effects of the studied biases on relative positioning are up to 10 cm for baseline length independent errors and up to 10 ppm for baseline length dependent errors. Applications of this technique are suggested for planning (pre-analysis) and assessment (post-analysis) in GPS production surveys.|
|Document Type:||Article de recherche|
|Issue Date:||1 March 1991|
|Open Access Date:||23 November 2016|
|This document was published in:||Manuscripta geodetica, Vol. 16, 28-53 (1991)|
|Collection:||Articles publiés dans des revues avec comité de lecture|
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