1 / 37

A Novel Real-Time Precise Positioning Service System:

A Novel Real-Time Precise Positioning Service System: Global Precise Positioning With Regional Augmentation Maorong Ge( maor@gfz-potsdam.de ), Xingxing Li, Jan Dousa, Hongzheng Cui, Gerd Gendt, Jens Wickert Junping Chen(SHAO), Xuan Zou(WHU) German Research Centre for Geosciences

keira
Download Presentation

A Novel Real-Time Precise Positioning Service System:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A Novel Real-Time Precise Positioning Service System: Global Precise Positioning With Regional Augmentation Maorong Ge(maor@gfz-potsdam.de), Xingxing Li, Jan Dousa, Hongzheng Cui, Gerd Gendt, Jens Wickert Junping Chen(SHAO), Xuan Zou(WHU) German Research Centre for Geosciences CSNC2011, Shanghai, China , 18-20 May 2011

  2. Network Real-Time Kinematic (NRTK) Using a local/regional reference network OBS. DOMAIN Representation NRTK Service Covers The Whole Chinese Territory? Global Precise Point Positioning Service Using a global reference network STATE DOMAIN Representation Initialization/Re-initialization takes 10-30 Min.. Global PPP + Regional Augmentation For All Real-Time Applications Real-Time Positioning Services

  3. EPOS-RT Software Global RT-PPP Service Regional Augmentation The Novel System Contents

  4. EPOS-RT Software Motivation Structure Progress

  5. EPOS-RT: Motivation • Requirement of: • New IGS Products • Multi-System, Multi-Technologies • LEOs, GEOs, Huge Networks • IGS Real-Time Pilot Project • GFZ Ongoing Projects • Decision: • Multi-Technology: GNSS SLR VLBI … • Multi-Function: Real-time/Post-mission; Static/Kinematic/Dynamic

  6. EPOS-RT: Structure Left Side: Post-Processing. Right Side: Real-Time

  7. EPOS-RT: Progress Since Sept. 2007 Already Available GPS/GLONASS Real-Time Clock Estimation GPS/GLONASS/LEO POD (Cui et al, EGU2011, Presentation) Regional Augmentation/NRTK (Li et al, EGU2011, Poster) Real-Time ZTD (Bender et al, EGU2011, Presentation) Embeddable User Software Further Coming GALILEO/COMPASS SLR IONO. Model

  8. GFZ Global RT-PPP Service Hardware Software IGS Real-Time Analysis Centre At GFZ New Development in PPP PPP Ambiguity Resolution Data Gap Connection

  9. Real-Time PPP Service (Hardware) Geostationary Satellite GNSS-satellites Correction Data Stream Correction data stream GNSS reference stations User terminal with GNSS receiver and communication unit and PPP software INTERNET Caster EPOS-RT Generation of correction information Orbit, clock, iono. UPD GNSS observations Internet connection

  10. EPOS-RT For Real-Time PPP Service Internet connection Control Unit RT Orbit Hourly Data RT ORB SRIF(Orb) IGS Hourly Data BNC BNC2SRIF SRIF(Clk)‏ OBS Streaming RT Clock SRIF2BNS ORB/CLK/UPD NTRIP Products Control Unit GPS receivers GPS receivers RT PPP RT PPP Pos&Time ZTD/STD NTRIP Products BNC2SRIF BNC2SRIF SRIF(PPP)‏ SRIF(PPP)‏ IGS Real-Time Analysis Center at GFZ

  11. Standard PPP Server

  12. Standard PPP Client

  13. GFZReal-Time Clock (Valid) IGS RT PPP Online Validation: http://igs.bkg.bund.de/ntrip/ppp

  14. New Development in PPP • PPP Ambiguity Fixing • To Shorten Convergence & To Improve Position Accuracy • Uncalibrated Phase Delay (UPD) • Data Gap Handling • To Avoid Re-Initialization • Temporal Stability of Atmo. Delays

  15. UPD Generation For PPPAMB

  16. UPD Generation For PPPAMB

  17. PPP+AMBFIX: 1-2 cm in Horizontal, 3-4 cm in Vertical. Initialization Time 15-20 Min.

  18. Impact Summary Integer Ambiguity Fixing Long (Re)Convergence Integer Ambiguity Fixing Data Gap Handling Expected NRTK Performance

  19. Regional Augmentation System Configuration Bias Representation Using UnDifferenced Obs. Corrections Realization of UD-Corrections Experimental Validation

  20. Principal: Unambiguous OMC • OMC of Station k to Satellite i • Unambiguous OMC (Ambiguity Known)

  21. Corrected Obs. Equ == PPP With Integer SD-Ambiguities How To Get The Integer UD-Ambiguities For L1&L2 ? Principal: Unambiguous OMC • Interpolated User Correction Interpolated Correction User Obs. Equ. Cor. Obs. Equ.

  22. Integer UD Ambiguities • “Consistent” Int. UD Amb. Instead of The True • Consistent == "Int. DD Amb. Constrained” Two Ways (Ambiguity Mapping): • Without Precise Sat. Clocks --- New NRTK • (Based On Fixed DD-ambiguities) • With Precise Sat. Clocks--- PPP Augmentation, • (Based On Fixed UD/SD-ambiguities) • Network Solution Not A MUST • There is no limitation on the Number of Reference Stations

  23. Generation Of Augmentation Info.

  24. PPP+Regional Augmentation Client

  25. New NRTK: Data Processing Data from Regional Reference Network Orbits & Clocks, UPDs from Global RTPPP Service BRD- (or Ultra Rapid) Orbits & Clocks Data Processing for Ambiguity-fixing (Baseline Mode) Data Processing for Ambiguity-fixing (PPP Mode) PPP +AMBFIX Fixed DD-ambiguities OMC wrt Orbits & Clocks RECEIVER With Reg. Info. Accuracy: < 2cm Initialization: DF < 2min SF < 10min Ambiguity Mapping Computation of Unambiguous OMCs CASTER

  26. Validation SAPOS: Simulated RT • DATA (Map: www.sapos.de) • SAPOS Data of 290 stations • Various receiver types • 30 seconds sampling rate • Reference Network • Selected 22 reference stations • Inter-station distance 184 km • Others are user stations • Software • EPOS-RT

  27. Results: Fixing Time (Lw+L1) • Lw+L1 can be fixed with 1 epoch data, On average 1.6 epochs, half of Lw (3 epochs) • LW+L1+ION.PAR can furthermore reduce the fixing time but slightly. Improvement found for cases where long fixing time needed.

  28. Results: Position Accuracy Accuracy of the Positions at the first fixed epoch Using Lw+L1 • Lw+L1 8, 6 and 21 mm in ENU, the same as L1 7, 6, and 20 mm • Lw+L1+ION, slightly worse than Lw+L1, but fixing is improved

  29. Validation (CORS): Real Time A Regional CORS Net Network • DATA • A Regional CORS Network. with 70 stations • Stream Data of 1Hz • Reference Network • Selected 13 reference stations Inter-station distance 150 km • User stations • Software • Newly Developed at GFZ in C++

  30. Validation: Real-Time Results • Every Minute Reset Filter • 90% Fixed With 1 Epoch, On average 3 s • Lw, 18, 14 and 34 mm ENU • Lw+L1 in development

  31. Summary of Augmentation • UD-OMC Based On “Integer UD Ambiguity” • Casted Station-By-Station • Instantaneous Ambiguity Fixing Achievable • Network Solution Not A MUST • Augmented PPP To Replace NRTK

  32. Global PPP With Regional Augmentation System Configuration Regional Augmentation PPP Clients

  33. Augmentation of PPP Service Standard PPP Services • Without Reg. Info. • Accuracy: • DF < 10 cm • SF < 40 cm • Initialization: • < 20 min CLOCK Global Info ORBIT, CLOCK IONOS Global Ref. Network ORBIT CASTER IONOS PPP +AMBFIX With Reg. Info. Accuracy: < 2cm Initialization: DF < 2min SF < 10min Obs.Residuals/OMC Regional Ref. Network CASTER Regional Info Obs. corrections Regional Augmentation / Network RTK Global Real-Time Precise Point Positioning With Regional Augmentation

  34. Generation Of Augmentation Info.

  35. PPP Clients

  36. Performance Of The Augmented PPP Service Without Regional Augmentation Open Ocean, … 5-10 cm, after 30 min., 3-5 cm after Ambiguity-Fixing (15 min) With Regional Augmentation Developed Cities, … 1-2 cm, within 1-2 min. depends on … Also For Single-Frequency And Low-Cost Receivers

  37. Further Work • As New Activity Under IGS-RTPP, EUREF • Operational Test For China With About 800 Reference Stations. • Operational Test As For Europe.

More Related