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Effects of azimuthal multipath asymmetry on long GPS coordinate time series

journal contribution
posted on 2023-05-17, 15:27 authored by Goebell, S, Matt KingMatt King
Carrier phase multipath is currently one source of unmodeled signals that may bias GPS coordinate time series significantly. We investigate the effect of simulated carrier phase multipath on time series of several sites covering the period 2002.0-2008.0 and spanning a range of observation geometries. High-, mid-, and low-latitude IGS sites are investigated as well as sites with significant signal obstructions. We examine the effect of multipath in different sectors of the sky, considering time-constant, horizontal reflectors at each of 0.1, 0.2, and 1.5 m below the antenna. The differences between a horizontally uniform multipath source are analyzed, and it is shown that positioning errors are generally larger when unmodeled carrier phase multipath is azimuthally heterogeneous. Using the adopted multipath model, height biases reach ±1 mm in case of the symmetric multipath and ±5 mm for the asymmetric multipath but this increases to being ±10 mm in the worst case. In addition to mean bias, low-frequency variations in the bias also exist, including periodic signals and leading to velocity biases of up to ±0.1 mm/year in the symmetric case and ±1 mm/year in the asymmetric case over the considered period. In contrast to the generally slowly varying observation geometry that is typically experienced, we show the effects of an abrupt change in geometry due to receiver/antenna hardware changes; in the case considered, we see changed pattern of temporal variation in the bias in addition to an instantaneous offset. © 2011 Springer-Verlag.

History

Publication title

GPS Solutions

Volume

15

Pagination

287-297

ISSN

1080-5370

Department/School

School of Geography, Planning and Spatial Sciences

Publisher

Springer

Place of publication

Tiergartenstr 17, Heidelberg, 69121 Germany

Rights statement

Copyright Springer-Verlag 2011

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the earth sciences