General activities

• Document the potential contributions of Global Navigation Satellite Systems to reference frame establishment and maintenance.
• Investigate the ties and their time evolution between GNSS Broadcast Frames like WGS84, PZ-90 and the upcoming GALILEO Reference Frame, and the ITRF.
• Examine deficiencies in the stability of the global GNSS station network, especially focusing on stations contributing to the ITRF2000 catalogue.
• Prepare a consolidated feedback concerning GPS, GLONASS and GALILEO frame establishment and improvement based on relevant experience in areas such as receiver site selection, installation and maintenance.
• Investigate the individual strengths and shortcomings of GPS, GLONASS and GALILEO for Reference System Realisation and work out synergies.
• Study the ties of regional and local frames realized by a permanently increasing number of active real-time GNSS networks.

Work schedule

Mid 2003 - Mid 2005 :

Compile a clear picture of the individual strengths and shortcomings of GPS and GLONASS for Reference System Realisation. This also includes inspection of stability of global GNSS ITRF core stations, the question of site-selection and maintenance and a documentation of the ties between the GPS and GLONASS broadcast frames WGS84, PZ-90 and the ITRF. Furthermore the contribution of the permanently increasing number of regional and local real-time GNSS networks for frame densification will be investigated.

Mid 2005 - Mid 2007 :

Focus on the upcoming GALILEO system. Based on the agreed reference network design we will investigate the quality of the tie and anticipated time evolution of the GALILEO Reference Frame with the ITRF. In addition the group will concentrate on expected synergies using a real GNSS observation network covering three satellite navigation systems for reference frame maintenance.