HR: 08:45h
AN: G31A-04 [Abstracts]
TI: Atmospheric Delay Modelling in GPS Analysis and its Influence on Geocenter and Earth
Rotation
AU: * Schuh, H
EM: harald.schuh@tuwien.ac.at
AF: Institute of Geodesy and Geophysics, Vienna Univ. of Technology
Gusshausstr. 27-29, Wien, 1040
Austria
AU: Tregoning, P
EM: pault@rses.anu.edu.au
AF: Research School of Earth Sciences, Australian National University, Canberra, ACT 0200
Australia
AU: Boehm, J
EM: johannes.boehm@tuwien.ac.at
AF: Institute of Geodesy and Geophysics, Vienna Univ. of Technology
Gusshausstr. 27-29, Wien, 1040
Austria
AU: Mendes Cerveira, P
EM: mendes@mars.hg.tuwien.ac.at
AF: Institute of Geodesy and Geophysics, Vienna Univ. of Technology
Gusshausstr. 27-29, Wien, 1040
Austria
AB:
A three-parameter continued fraction of the form 1/sin(elevation) is usually used in the analyses of GPS data as an analytic
expression for mapping the atmospheric zenith delay to the line-of-sight. The coefficients 'a' of this continued fraction
form are either simple functions of day of year and station coordinates (Niell Mapping Functions (NMF) or Global Mapping
Functions (GMF)) or they are determined from numerical weather models (Isobaric Mapping Functions (IMF) or Vienna Mapping
Functions (VMF)). Biases and other systematic differences between the mapping functions cause systematic changes of the
station coordinates and influence in particular the station heights. As these biases are different in various regions of the
Earth, apparent effects like geocenter motion, flattening of the Earth and variations in x- and y-pole can be created when
using obsolete mapping functions. These effects especially occur at annual periods. The influence of the differences between
the mapping functions mentioned above is simulated by using ERA40 data (40 years Re-Analysis data from the European Centre of
Medium-Range Weather Forecasts). These simulations are compared with results from one year of GPS analysis with the
GAMIT/GLOBK software.
DE: 1220 Atmosphere monitoring with geodetic techniques (6952)
DE: 1229 Reference systems
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: Fall Meeting 2005