Improvement of the Analysis Strategy of GEONET

Yuki HATANAKA, Toyohisa IIZUKA, Masanori SAWADA, Atsushi YAMAGIWA, Yukie KIKUTA, James M. Johnson, Christian Rocken


A new analysis strategy of the GPS Earth Observation NETwork (GEONET) of the Geographical Survey Institute (GSI), Japan, was proposed by taking into account improved models and methods. The routine analysis system was upgraded and reanalysis of the data of the past five years of GEONET was carried out applying the new analysis strategy. Comparison of the new and old solutions shows that the quality of the solutions is quite uniform for the entire period and the root mean square coordinates are reduced by about 50 % after removing the linear and seasonal trends and the event offsets. The improvement of the precision of the vertical component provides us more opportunities for interpretations of the vertical crustal deformations.


1. Introduction
2. Overview of GEONET
3. The Changes of the Analysis Strategies
  3.1 New Phase Maps Specific for Antenna-Monument Types
  3.2 Ocean Loading Tide Model
  3.3 Network configuration
  3.4 Coordinates and Velocity of Stations to be Constrained
  3.5 Reference Frame of Satellite Orbits and Earth Rotation Parameters
  3.6 Troposphere Modeling
  3.7 Other Changes Associated with the Upgrade of the Software
4. Reanalysis of the GEONET Data
5. Comparison of the Time Series of Coordinates and Baseline Components
6. Evaluation of Quality of the New Solutions
  6.1 Modeling of the Baseline Time-Series
  6.2 Long Term Repeatability
  6.3 Site Velocity
  6.4 Comparison of GPS/PWV with Radiosonde
7. Discussions
8. Conclusions