The impact of microwave absorber and radome geometries on GNSS measurements of station coordinates and atmospheric water vapour |
| |
Authors: | T Ning G Elgered JM Johansson |
| |
Institution: | Department of Radio and Space Science, Chalmers University of Technology, Onsala Space Observatory, SE-439 92 Onsala, Sweden |
| |
Abstract: | We have used microwave absorbing material in different geometries around ground-based Global Navigation Satellite System (GNSS) antennas in order to mitigate multipath effects on the estimates of station coordinates and atmospheric water vapour. The influence of a hemispheric radome – of the same type as in the Swedish GPS network SWEPOS – was also investigated. Two GNSS stations at the Onsala Space Observatory were used forming a 12 m baseline. GPS data from October 2008 to November 2009 were analyzed by the GIPSY/OASIS II software using the Precise Point Positioning (PPP) processing strategy for five different elevation cutoff angles from 5° to 25°. We found that the use of the absorbing material decreases the offset in the estimated vertical component of the baseline from ∼27 mm to ∼4 mm when the elevation cutoff angle varies from 5° to 20°. The horizontal components are much less affected. The corresponding offset in the estimates of the atmospheric Integrated Water Vapour (IWV) decreases from ∼1.6 kg/m2 to ∼0.3 kg/m2. Changes less than 5 mm in the offsets in the vertical component of the baseline are seen for all five elevation cutoff angle solutions when the antenna was covered by a hemispheric radome. Using the radome affects the IWV estimates less than 0.4 kg/m2 for all different solutions. IWV comparisons between a Water Vapour Radiometer (WVR) and the GPS data give consistent results. |
| |
Keywords: | GNSS antennas Multipath Microwave absorbing material Radome Atmospheric water vapour Water Vapour Radiometer |
本文献已被 ScienceDirect 等数据库收录! |