有朋自远方来，不亦乐乎 ! “How happy we are, to meet friends from afar!” - Confucius Welcome to Stanford!

From Current GNSS Signal Observations to a Future Global Network of Civil Monitoring Grace Xingxin Gao/ 高醒心 (with the help of many) Stanford University For the Civil Aviation Administration of China

3 Azimuth/Elevation Control Current: Stanford GNSS Monitor Station (SGMS) with 1.8 m Dish Antenna L-band Feed Cavity Filter Nova for Windows Satellite Tracking Software Agilent Vector Signal Analyzer (VSA) Low Noise Amplifier 45dB 15 m cable On-demand operation 1.8 m steerable dish antenna –High gain –Directional Flexible data collection system

4 Using SGMS to Analyze GNSS Signals GNSS Frequency Plan Observe frequency spectra Study signal structures Analyze interoperability issues

5 Compass-M1 Observations E2 PSD (dB/Hz)E5b PSD (dB/Hz)E6 PSD (dB/Hz) frequency (MHz) First satellite Compass-M1 launched on 4/14/2007 Second satellite Compass-G2 launched on 4/14/2009

6 GPS IIR-20 Observations L1 PSD (dB/Hz)L5 PSD (dB/Hz)L2 PSD (dB/Hz) frequency (MHz) GPS IIR-20 (SVN 63) is the first GPS satellite with L5 payload GPS IIR-20 was launched on 3/24/2009, and L5 transmission was turned on 4/10/2009

7 Access to Other Facilities SRI 45.7 m radio telescope antenna in the Stanford hills, Stanford, California ITS 20 m parabolic antenna, Table Mountain, Colorado

8 Signal Observations from Stanford SRI Dish and Table Mountain Dish A clean L5 spectrum captured by the 45.7m SRI dish Signal observations on the first day of GPS IIR-20 L5 turn-on A full spectrum of all GPS frequency bands captured by the 20m dish at Table Mountain

9 Vision – a Global Monitoring Network for Evaluating ARAIM Prototyping the Integrity Machine of the Future: Civil Monitoring Testbed

10 Testbed Architecture Space Segment (GPS, WAAS, Compass, Galileo, GLONASS) Control Segment (e.g., SGMS) User Segment (e.g., NSTB Sites)

11 Phase I: SU ARAIM Prototype Plan Multi-constellation multi-band receiver ARAIM implementation SV signal-in-space error analysis Display & GUI SGMS 1.8m dish Automatic data logging Post-processing investigation Trigger Anomaly Investigation (Control Segment) Integrity Monitoring Based on ARAIM (User Segment)

12 Global testbed for ARAIM evaluation Incorporate other sites: FAA TC, DLR (Germany), NCKU (Taiwan), perhaps CAAC ATMB and many others. Phase II: Civil Monitoring Testbed Roll-out

13 Acknowledgments Collaborators within the GPS Lab –Prof. Per Enge, Dr. Todd Walter, Dr. Juan Blanch, Dr. Eric Phelts, Dr. Sherman Lo, Dr. Dave De Lorenzo, Doug Archdeacon, Alan Chen, Liang Heng, etc. Collaborators outside of the GPS Lab –Universities and research institutes Prof. Dennis Akos, Univ. of Colorado, Boulder Mike Cousins and John Ciboci, SRI International –Industry Stuart Riley, Trimble Inc. FAA sponsors –JC Johns, Leo Eldredge, Deborah Lawrence, Carlos Rodriguez, Deane Bunce, Ted Urda and Jason Burns