Atmospheric Impacts on GPS observations in Antarctica

1. Atmospheric Impacts on GPS observations in Antarctica AGS 2002, Wellington, New Zealand

2. Project Work Plan 2002-04 • Facilitate access to GPS observations from permanent GPS sites and SCAR GPS epoch campaigns for computation of atmospheric delay to GPS signals • Examine the correlation with magnetic storms • Research impact of differing levels of solar and meteorological activity on Antarctic GPS observations • Report on participation in international studies AGS 2002, Wellington, New Zealand

3. Project Work Plan 2002-04 • Report on project findings • Continue collaboration with Iono_WG of IAG • Search for existing research (PhD) that is currently being conducted – may be able to assist with data analysis • Develop recommendations for future GPS observations to minimise impact on GPS network surveys AGS 2002, Wellington, New Zealand

4. History of Project • Established at the XXVI SCAR meeting in Tokyo in 2000 • Aim is to investigate the iononspheric impact on the quality of GPS observations in Antarctica • First results were presented at AGS’01 in St Petersburg in 2001 AGS 2002, Wellington, New Zealand

5. History of Project • The results of the time series analysis from the data of European Permanent Network as well as from Antarctic IGS stations were presented in Shanghai • The analyzed data was from the period a few days either side of the ionospheric storm on 64DOY2001 (& came from three Antarctic IGS stations, i.e. Davis, Mawson, and Casey) AGS 2002, Wellington, New Zealand

6. History of Project • The project was extended at XXVII SCAR • to allow for the processing of additional data from other Antarctic stations • to analyze longer time series of GPS solutions together with ionospheric data AGS 2002, Wellington, New Zealand

7. Numerical Experiments • left hand side of the graph indicates the vicinity of 64DOY2001 where took place the ionoshperic storm • area on the right hand side corresponds to a series of strong ionospheric disturbances AGS 2002, Wellington, New Zealand

8. Variations of TEC in 2001 for BOGO and DAV1 stations from IONEX files AGS 2002, Wellington, New Zealand

9. Next slide shows information on periods of geomagnetic storms as predicted by IPS Geomagnetic Disturbance Warning AGS 2002, Wellington, New Zealand

10. Variations of TEC in October-November 2001 for BOGO and DAV1 stations from IONEX files AGS 2002, Wellington, New Zealand

11. Time series of GPS solutions for OHIG-MCM4 vector components, its length and a number of single differences used for solving a vector AGS 2002, Wellington, New Zealand

12. Time series of TEC for CAS1 from IONEX (a), from IONO-WG (b), and MAV1-CAS1 vector length (c) AGS 2002, Wellington, New Zealand

13. CONCLUSIONS • Investigation of atmospheric impact on GPS measurements in a new dimension leads toward: • modeling the influence the environmental effects and internal errors of GPS system; • correcting GPS solutions with the developed models; • more reliable accuracy estimate of GPS solutions; • studying short term variations of the environmental effects and internal errors of GPS system. AGS 2002, Wellington, New Zealand

14. Future Activities • The next step of the project concerns the analysis of the tropospheric impact on GPS solutions obtained from processing GPS data from Antarctic stations AGS 2002, Wellington, New Zealand

15. ACKNOWLEDGMENT The research was supported by the Institute of Geodesy and Cartography in Warsaw and was partially financed by the Polish State Committee for Scientific Research (grants No 9T12E01918, 8T12E05321 and 8T12E04520). AGS 2002, Wellington, New Zealand