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Temporal Stability of GPS Transmitter Group Delay Variations
Susanne Beer1, Lambert Wanninger2
1Geodätisches Institut, Technische Universität Dresden, 01062 Dresden, Germany. susanne.beer@tu-dresden.de.
Sensors (Basel, Switzerland)
|May 31, 2018
Summary
Global Navigation Satellite System (GNSS) transmitter antenna group delay variations (GDV) are stable over time, impacting precise positioning. Inconsistencies in GPS GDV are linked to receiver, not temporal, factors.
Area of Science:
- Geodesy and Geomatics
- Satellite Navigation Systems
- Atmospheric Science
Background:
- Group Delay Variations (GDV) in Global Navigation Satellite System (GNSS) transmitter and receiver antennas significantly impact precise code applications.
- For the Global Positioning System (GPS), these variations can reach up to 1 meter in the ionosphere-free linear combination.
- GPS transmitter contributions to GDV can be as high as 0.8 meters peak-to-peak across the full nadir angle range.
Purpose of the Study:
- To verify the assumption of time-invariance for GPS transmitter antenna GDV.
- To determine daily individual satellite GDV for GPS transmitter antennas over an extended period (more than two years).
Main Methods:
- Utilized dual-frequency observations from globally distributed reference stations.
- Employed multipath combination analysis of the observational data.
- Calculated daily individual satellite GDV for GPS transmitter antennas.
Main Results:
- The determined GPS GDV exhibit stability within a few centimeters for C1, P2, and the ionosphere-free linear combination.
- Confirmed the temporal stability of GPS transmitter antenna GDV over the observation period.
- Identified receiver properties as the cause for inconsistencies in Space Vehicle Number (SVN) 55 GDV compared to previous studies.
Conclusions:
- GPS transmitter antenna GDV are stable over time, supporting their use in precise positioning applications.
- Temporal instabilities do not explain discrepancies in GDV for specific satellites like SVN 55.
- Receiver-related factors are the primary cause of observed inconsistencies in GPS GDV, highlighting the importance of receiver characterization.
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