WHU's Developments for the GPS Ultra-Rapid Products and the COMPASS Precise Products C. Shi; Q. Zhao; M. Li; Y. Lou; H. Zhang; W. Tang; Z. Hu; X. Dai; J. Guo; M.Ge; J. Liu 2012 International GNSS Workshop July 23-27, 2012 University of Warmia and Mazury (UWM) Olsztyn, Poland
Outline Introduction of PANDA software Ultra-Rapid Products from WHU COMPASS Precise Products Summary
Software and Platform PANDA : Positioning And Navigation Data Analyst To derive possible information from GNSS/SLR/ VLBI/DORIS data Real-time Processing function from 2007 Current Applications POD of GNSS (GPS, GLONASS, COMPASS, GALILEO) POD of LEOs (CHAMP, GRACE, COSMIC, JASION, HY-2A,ZY-3) Ionosphere Modeling Huge Network data processing, PPP SINEX Combination 3
PANDA System Structure
Ultra-Rapid Products from WHU
Analysis Strategy Summary ESTIMATED PARAMETERS (APRIORI VALUES AND CONSTRAINTS) Adjustment Station coordinates Satellite clock Receiver clock Orbits Satellite attitude Troposphere Ionospheric corrections Ambiguities Earth Orient.Parameters (EOP) Weighted least squares algorithm All coordinates are estimated in the IGS08 realization of the ITRF2008. The datum is realized by tightly constraining the processed Reference Frame stations to their current coordinate values. solved for at each epoch (white noise process) solved for at each epoch (white noise process); one clock fixed and used as a time reference 6 parameters for initial position and velocity 5 parameters for solar radiation pressure modeling, 24 hours estimation and 24 hours prediction yaw rate is estimated for BLOCK II/IIA/IIF satellites during shadow crossing zenith delay: zenith delay parameters for each station with 1 hour intervals mapping function: wet Global Mapping Functions (GMF) zenith delay epochs: each integer hour gradients: north and east horizontal delay are estimated for each station in daily intervals Not estimated (ionosphere free based analysis) ambiguities are fixed according to Ge et al.(2005) X and Y pole coordinates, and UT1 UTC represented with continuous piece wise linear function 6
Ultra-rapid orbit Quality http://acc.igs.org/ Better than 5cm compared with IGS ultra-rapid orbit 7
Ultra-rapid orbit precision compared with IGS Rapid About 3cm compared with IGS rapid orbit 8
Orbit transformation results compared to Rapid orbit 9
Improvement step by step 1) Improvements of the Ultra-rapid orbits from WHU 2) Steps for continuous improvement Prediction for the eclipse satellites New strategy for choosing stations used for the Ultra-rapid POD.. 10
Application (real-time GPS products) 0.25 Statistical RMS of real-time satellite clock product 0.20 Clock difference with igs final solution (ns) 0.15 0.10 0.05 0.00 P rn 32 31 30 29 28 27 26 24 23 22 21 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 44 Clock Streams:CLK15 & CLK16 Real-time evaluation by BKG http://igs.bkg.bund.de/ntrip/ppp#scene3 11
Application (Augmentation Service System in China) dual-frequency Unit: m single frequency 12
COMPASS Precise Products
COMPASS Precise Products Status of COMPASS POD and SPP performance of COMPASS Precise positioning using COMPASS Plan for providing precise products of COMPASS
Status of COMPASS Current operational Satellites: 4GEO+5IGSO+2MEO 2012: 5GEO+5IGSO+4MEO(Regional Service) 2020: 5GEO+3IGSO+27MEO(Global Service) 2012 July,2012 C10 C07 C12 2020 C11 C05 C03 C01 C04 C09 C08 C06
POD of COMPASS The Netherlands Greece Uramqi Lhasa Xi an Chengdu Haerbin Beijing Wuhan Shanghai Abu Dhabi Hongkong Singapore Indonesia Australia South Africa COMPASS Network by WHU (Wuhan University) 17 sites: UB240-CORS dual-frequency GPS/COMPASS civil receivers 5 sites: three-frequency COMPASS monitoring receivers
POD of COMPASS 4GEO+5IGSO 1-30,Jun,2012 The Netherlands Greece C10 Uramqi Xi an Lhasa Chengdu Haerbin Beijing Wuhan Shanghai C07 Abu Dhabi Hongkong Indonesia C05 C03 C01 C04 Singapore C08 South Africa C09 Australia C06 Indonesia
Precise Orbit Determination Data:2012.06.01 ~2012.06.30 Observation Cut off elevation Data length/sampling rate EOP Ambiguity Station coordinate Relativistic effects Station displacement Tropospheric delay Ionospheric delay Satellite clock Receiver clock Orbit parameters Parameters and Models LC and PC 10 degree 3days/300s Fixed to IERS float Constraint to IGS08 Yes Solid earth, pole tide, ocean loading(iers 2010) Saastamoinen + GMF, PWC Eliminated by using LC and PC white noise white noise X Y Z Vx Vy Vz Bern SRP (D 0 Y 0 B 0 B C B S ) 18
Orbit Overlap difference (Radial) Overlap orbit differences [cm] 18 16 14 12 10 8 6 4 2 C06: 6.8 cm C07: 6.2 cm C08: 6.3 cm C09: 4.3 cm C10: 4.6 cm Ocerlap orbit differences [cm] 45 40 35 30 25 20 15 10 5 C01: 11.6 cm C03: 6.2 cm C04: 11.0 cm C05: 9.2 cm 0 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 Day of year 2012 0 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 Day of year 2012 Radial RMS: 10cm 19
Orbit Overlap difference 3D (Jun, 2012) 275 GEO 250 Along: 15.5 cm Cross: 16.2 cm Radial: 5.2 cm Along: 156.6 cm Cross: 7.7 cm Radial: 5.5cm 225 200 175 Cross Difference (cm) Overlap orbit differences [cm] IGSO 150 125 100 75 50 C01 Cross C06 Cross 45 40 35 30 25 20 15 10 5 0-5 -10-15 -20-25 -30 25 0 7200 14400 21600 C03 Cross C07 Cross 28800 36000 C04 Cross C08 Cross 43200 50400 C05 Cross C09 Cross 57600 64800 C10 Cross 72000 79200 86400 Seconds of Day 160 (Seconds) 0 C01 C03 C04 C05 C06 C07 C08 C09 C10 DOY 160 of 2012 C01 Along C06 Along C03 Along C07 Along C04 Along C08 Along C05 Along C09 Along C10 Along 100 0 Radial Difference (cm) Along Difference (cm) 50-50 -100-150 -200-250 -300 0 7200 14400 21600 28800 36000 43200 50400 Seconds of Day 160 (Seconds) 57600 64800 72000 79200 86400 C01 Radial C06 Radial 18 16 14 12 10 8 6 4 2 0-2 -4-6 -8-10 -12-14 -16-18 0 7200 14400 21600 C03 Radial C07 Radial 28800 36000 C04 Radial C08 Radial 43200 C05 Radial C09 Radial 50400 57600 64800 C10 Radial 72000 79200 86400 Seconds of Day 160 (Seconds) IGSO 3D RMS: 30cm GEO: Biased in the Along direction 20
SLR Validation 0.20 C08 7825 7237 0.15 0.10 SLR validation (m) 0.05 0.00-0.05-0.10 about 10cm -0.15-0.20 56080 56085 56090 56095 56100 56105 56110 Mjd (day)
CLK Performance Hadamard Variance for GEO: CO1 Allan Variance for GEO: CO1 22
CLK Performance Hadamard Variance for IGSO: CO8 Allan Variance for IGSO: CO8 23
SPP performance of COMPASS(4GEO+5IGSO)
URE of broadcast ephemeris is about 1.5 meters, compared to the precise orbit products from Wuhan University Compared to CODE ionosphere model, the Beidou Klobuchar Ionosphere mode( BD K8) is better than 2.0 meter within northern hemisphere
SPP performance of COMPASS(4GEO+5IGSO) The typical multipath effect is about 0.5 meter using UNICORE receiver The receiver noise effect is about 0.5 with UNICORE receiver
SPP performance of COMPASS(4GEO+5IGSO)
SPP performance validation STATION Performance of SPP (95%,m) Validation using real data(95%,m) BEIJ 8.87 8.22 WUHN 9.15 10.74 SHAO 9.64 10.92 XIAN 9.18 8.54 CHDU 7.60 9.311 HERB 12.45 12.48 HONK 6.79 5.726 ABDB 18.85 15.07 PERT 14.02 11.64
COMPASS PPP solutions 0.05 0.04 0.03 0.02 0.01 0-0.01-0.02-0.03-0.04-0.05 0.09 0.07 0.05 0.03 0.01 0.06 0.05 0.04 0.03 The Netherlands 0.02 e n Haerbin Uramqi 0.01 Beijing Xi an0 1 3 5 7 9 11 13 15 17 19 210.06 23 25 u Greece Lhasa Shanghai -0.01 1 3 5 7 9 11 13 15 17 19 21 23 25 0.05 Chengdu Wuhan 0.04-0.02 Station Name -0.03 Hongkong 0.03 E(cm) Abu Dhabi N(cm) U(cm) -0.04 0.02 Indonesia e n CHUN 0.01 0.756 0.637 2.005 Singapore 0 u KUNM 0.02-0.01 1 3 5 7 0.500 9 11 13 15 17 19 210.194 23 25 0.929 LINT -0.02 0.015 0.929 0.603 Australia 1.949-0.03 0.01 KASI -0.04 South Africa 1.172 0.673 2.523 0.005 e n WLMU 0.841 0.637 0 2.279 1 3 5 7 9 11 13 15 17 19 21 23 25 u -0.005 e u e u -0.01-0.03-0.05 1 2 3 4 5 6 7 8 9 10111213141516171819202122232425-0.01-0.015-0.02 29
COMPASS baseline solutions 16.8 km 0.010 0.008 0.006 Beidou baseline static solutions compared to GPS de dn du 0.004 21.7 km 12.7 km 0.002 4.3 km m 0.000-0.002 9 km -0.004 5.6 km -0.006-0.008 WUHN-HBCS WDKJ-HBCS WUHN-WDKJ WUHN-CWKX HBCS-CWKX WDKJ-CWKX 4.3 km 5.6 km 9.0 km 12.7 km 16.8 km 21.7 km -0.010 Baseline 9km Kinematic baseline 30
Plan for COMPASS precise products Ultra-rapid products (Oct.,2012) Orbit and Clock products ZTD,Ion. coordinates Final products (Oct.,2012) Orbit and Clock products ZTD,Ion. coordinates Data : real-time stream(1s) and files(30s) Partners access (Oct.,2012) All users access (Jun., 2013), M-GEX Agreements with the partners Meet the guidelines of IGS 31
Summary PANDA software Ultra-rapid real-time products COMPASS analysis Ultra-rapid products from WHU Summary ~3cm compared with IGR are used for real-time GPS clock products, Augmentation Service System in China COMPASS results orbit: ~10cm in radial PPP 1~2cm compared with GPS solution Comparing with GPS only, emerging Compass data could improve the accuracy of baseline kinematic solution about 10-20% Precise COMPASS products will be available around Oct, 2012 from WHU.
The GNSS Research Center of Wuhan University shi@whu.edu.cn zhaoql@whu.edu.cn lim@whu.edu.cn