Modelling of Site Specific Effects and the Impact upon Local Tie Residuals
Abstract
It is well known that site specific effects such as far-field and near-field multipath do not average out over time and that the time varying geometry of GNSS constellations leads to draconitic aliasing of these unmodelled signals into station position time series. Studies have also shown that the structures on which GNSS antennae are mounted introduce near-field multipath effects that can cause position errors reaching magnitudes of 4-5 cm at Polar Regions, and that unmodelled radomes have a significant impact on the Phase Centre Variation (PCV) of Global Positioning System (GPS) antennae, also leading to biases in coordinate time series. In this work we evaluate the efficacy of using empirical site models (ESM) to improve the realisation of the combined multi technique international terrestrial reference frame (ITRF). We use a comparison of local tie residuals, at ITRF, VLBI, SLR and GPS co-location sites, obtained from GPS solutions with and without Empirical Site Models applied. We will show that in order to achieve 1mm local tie residuals between the different space geodetic observation techniques, site specific modelling needs to be taken into consideration.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.G51C..06M
- Keywords:
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- 1229 GEODESY AND GRAVITY / Reference systems;
- 1294 GEODESY AND GRAVITY / Instruments and techniques