1. SHA: the GNSS Analysis Center at SHAO Junping Chen, Bin Wu, Xiaogong Hu Haojun Li, Xiao Pei, Yize Zhang Shanghai Astronomical Observatory (SHAO) junping@shao.ac.cn

2. 22 Content  IGS Products status  Challenges in GNSS data analysis  GNSS Analysis Center at SHAO  SHA Products  Summary

3. 33 IGS Products Status  IGS: Free and volunteer….., but service should follow NASA’s policy Home page and ftp are denied for Chinese IP since 2011 Doy 327 (Nov. 23)… Alternate: IGN mirror GPS Orbits (cm) GPS clocks (ns) Pole (mas) Lod ( µ s) Coordinates(mm)/ velocities(mm/year) IGS2.50.020.0310 Horizontal: 3.0/2.0 Height: 6.0/3.0 IGR2.50.030.0410 IGUA3.00.05 10 IGUB5.01.50.2050

4. 44 Challenges in GNSS data analysis Multi-system data analysis and handling of new frequencies/data types  Current standard settings L1/L2 ionosphere-free combination All products (orbits & clocks & coordinates …) based on this… But…  New System & satellites & Frequencies

5. 55 Challenges in GNSS data analysis Multi-system data analysis and handling of new frequencies/data types  Current standard settings L1/L2 ionosphere-free combination All products (orbits & clocks & coordinates …) based on this… But…  New System & satellites & Frequencies Clock difference between L1/L2 comb. And L1/L5 comb. Montenbruck etc, GPS solutions

6. 66 Challenges in GNSS data analysis Multi-system data analysis and handling of new frequencies/data types  Current standard settings L1/L2 ionosphere-free combination All products (orbits & clocks & coordinates …) based on this… But…  New System & satellites & Frequencies IGS MGEX:  call for data (GPS/GLONASS/GALILEO/BD/QZSS)  Experience in M-GNSS data analysis  Resolution in bias issues  New standards/suggestions for products

7. 77 Combined GNSS analysis model Instrument delay Same for all GPS; Glonass: per Freq. or per sat. Satellite clock for GPS and Glonass

8. 88 Combined GNSS analysis model Instrument delay Same for all GPS; Glonass: per Freq. or per sat. Inter-system bias (instrument delay bias) as observed at each station. D Satellite clock for GPS and Glonass

9. Station inter-system instrument bias Site: SHAO (CMONOC), GPS+GLONASS observations Spanning from: Doy 165 - 365 2011 Constant bias parameter per Glo sat. at Daily/12h/6h/hour interval Parameter interval make differences!!(not shown here) 9

10. 10 Challenges in GNSS data analysis Huge network solution: Number of stations R. Ferland. 2010

11. 11 Challenges in GNSS data analysis Huge network solution: Number of satellites

12. 12 Challenges in GNSS data analysis Huge network solution: Number of parameters

13. 13 Challenges in GNSS data analysis Real-time GNSS analysis RT-PP network, BKG

14. 14 Challenges in GNSS data analysis Real-time GNSS analysis Stream delay and PPP accuracy J. Chen etc, Marine Geodesy

15. 15 SHA: GNSS data analysis at SHAO 15 Group of GNSS Data Analysis and Applications at SHAO (GGDAA) http://www.shao.ac.cn/shao_gnss_ac  Applied for the IGS Multi-GNSS data analysis (IGS M-GEX)Multi-GNSS data analysisIGS M-GEX  Working towards GGOS-C  Data and Analysis Center for CMONOC network (SHA) Daily routine for global GNSS network + CMONOC network  Towards Compass/Beidou Analysis center

16. 16 SHA: GNSS data analysis at SHAO 16 Group of GNSS Data Analysis and Applications at SHAO (GGDAA) http://www.shao.ac.cn/shao_gnss_ac  GNSS orbits  GNSS clocks: 30 seconds for GPS & GLONASS  Coordinates & Reference frame Improving China Terrestrial Reference Frame  GNSS Time Offset (TO)  Trop. ERP. Etc.

17. GPS/GLONASS Network IGS network analyzed at SHAO 17

18. CMONOC Network Crustal Movement Observation Network of China (CMONOC): 260 Permanent + ~2000 Campaign GNSS stations Average baseline: 200~300 km 18

19. CMONOC Network Crustal Movement Observation Network of China (CMONOC): 260 Permanent + ~2000 Campaign GNSS stations Average baseline: 200~300 km 19

20. 20 Products of SHA: e.g. GNSS orbits GNSS Orbits  GPS+GLONASS  Compared to IGS  <2 cm for GPS; <5 cm for GLONASS

21. 21 Products of SHA: e.g. GNSS orbits GNSS Orbits  GPS+GLONASS  Compared to IGS  <2 cm for GPS; <5 cm for GLONASS

22. 22 Products of SHA: e.g. GNSS clocks GNSS clocks: 30 seconds  GPS+GLONASS  Compared to IGS  <0.05 ns for GPS; <0.15 ns for GLONASS

23. 23 Products of SHA: e.g. GNSS clocks GNSS clocks: 30 seconds  GPS+GLONASS  Compared to IGS  <0.05 ns for GPS; <0.15 ns for GLONASS

24. 24 GNSS system Time Offset model Broadcast GLONASS clocks GLONASS clocks from Multi-GNSS solutions, using GPSt as reference TO= GLONASST – GPSt = [GLONASST – UTC(SU) ] – [GPSt - UTC(USNO)] + [UTC(SU)-UTC(USNO) ] GPS Broadcast BIPM bulletin GLONASS Broadcast Solution 1: Solution 2:

25. 25 System Time Offset: GLONASST – GPSt SHA: TO from GNSS routines at SHAO BRDC: TO based on Predicted value from GPS/GLONASS broadcast (UTC(SU)-UTC(USNO) not considered) General good agreement at 5ns level (broadcast clock accuracy) Targeting to improve inter-operation: GPS+GLONASS GPS/GLONASS system Time offset

26. 26 Summary SHA: GNSS Analysis Center at SHAO Facilities supporting GNSS research & applications http://www.shao.ac.cn/shao_gnss_ac

27. 27 Thank you! http://www.shao.ac.cn/shao_gnss_ac